HK40032875A

HK40032875A - Medical device and method for management of ocular axial length growth in the context of refractive error evolution

Info

Publication number: HK40032875A
Application number: HK62020022281.3A
Authority: HK
Inventors: 帕特里克·西马德; 雷米·马科特-科拉德; 珍·布兰卡德; 兰吉斯·米肖德
Original assignee: 蒙特利尔大学; 帕特里克·西马德; 雷米·马科特-科拉德; 珍·布兰卡德
Priority date: 2017-11-24
Filing date: 2018-11-23
Publication date: 2021-04-01

Description

Medical devices and methods for managing eye axial length growth against the background of ametropia development

Technical Field

The present invention relates to the field of ophthalmic medical devices and methods for treating refractive errors, and more particularly, to medical devices and medical methods for managing axial growth of the eye.

Background

Myopia is a current refractive error characterized by the perception of a blurred image at distance. This refractive error was considered common a few years ago and is now considered an important risk factor for ocular pathology over time. In fact, the World Health Organization (WHO) has warned public health agencies in 2016, and worldwide myopia prevalence has increased, with smaller age, and increasing severity of the disease, which can lead to glaucoma, retinal detachment, and macular or choroidal neovascularization.

The world health organization has considered the basic research results published over the last decade, which suggests that higher degrees of myopia (-above 5 diopters) and/or longer axial lengths of the eye (above 26 mm) represent significant risk factors for conditions that may affect ocular health and visual acuity over time.

It also proposes different clinical strategies which show successful results in terms of slowing the rate of progression of myopia and/or ocular axial length. These interventions can be categorized into 3 classes: lifestyle management, visual and optical management, and medication.

Lifestyle management advocates outdoor activities of at least 45 minutes per day, but preferably two hours, especially before myopia occurs. It also suggests that the use of computers, tablets and near work, as well as lighting conditions and other ergonomic aspects associated with school or office work, can cause myopia. Visual intervention is intended to correct any binocular vision problems found during eye examination, in particular the following factors: near strabismus (natural eye deviation), accommodation/convergence ratio and accommodation lag. Visual axis correction, vision treatment and optics may be used alone or in combination to address binocular vision. The presence of balanced and invariant binocular vision is demonstrated to prevent the onset and progression of myopia.

Any problems with adjustment can be solved by using optics designed with an additional part that provides an additional degree (add-power). Thus, the presence of any of these abnormalities may affect the selection and design of optics for managing myopia and axial length of the eye. For example, a given individual who shows a high accommodative lag (e.g., +1.25 diopters) and who is unresponsive to vision therapy will be compensated by wearing a pair of lenses or contact lenses that display an add power between +1.50 diopters and +2.50 diopters. The same device may be used to control or correct myopia but additional components may be used to restore its natural accommodation. In this case, the additional degree should be increased significantly to meet both requirements.

The optical strategy is based on the fact that the light rays entering the eye should be focused in parallel or in front of the peripheral retina, rather than behind the retina, as is the case with conventional glass or contact lenses. This goal is more difficult to achieve with eyeglasses, but is very feasible in contact lenses.

Two types of contact lenses were used, the first being rigid contact lenses, worn overnight, and conforming to a concept known as Orthokeratology (OK). In fact, the lens helps to shape and deform the cornea to affect the peripheral refraction. If the design is reasonable, the OK lens has good tolerance and does not bring higher risk compared with the long-time wearing of soft glasses. The second option emphasizes the use of soft multifocal contact lenses worn during the day. Although these lenses are primarily used to correct adult hyperopia, it has also been found effective for far central lenses and, to a lesser extent, near central multifocal lenses to partially control myopia progression. Currently, most current designs of multifocal lenses are limited in the add power (+0.50 diopters to +3.00 diopters) they provide. Their design is also different. For example, some designs use a fixed interval. In this case, a commercial design with a higher degree of addition would result in far distance blur, which is not appropriate. To limit this effect, the central zone should be designed larger or the add power should be limited to +2 diopters. Another strategy is to over-subtract the patient (i.e., provide a higher diopter of the lens for distance than the patient), which may be detrimental to binocular vision balance and the long-term impact on myopia progression is unknown. Other designs produce a hyperopic correction and add an additional power (positive asphericity) from the center to the periphery, followed by a constant increase. In addition, some new lens designs are based on the principle of expanding the depth of focus to correct hyperopia. These new lens designs produce high add powers and are pupil independent. They are successfully used to treat myopia without examination. With few exceptions, all of these prior art lenses are typically not customizable.

Furthermore, pharmacological approaches imply the use of either commercially available (atropine @ up to 1% concentration) or co-drugs (atropine @ 0.01% - @ 0.5% concentration, 1 drop per day of administration) or other non-commercially available drugs (e.g. pirenzepine). The mechanism of action of atropine is not fully understood, but clinical results show that it is most effective in all strategies for controlling myopia or progression of axial length of the eye, especially at higher concentrations (1%). As long-term safety has not been studied and because of the large number of side effects and rebound effects when used at higher concentrations, its use is retained when optical intervention cannot be considered or achieved, or as an adjuvant therapy when the means applied cannot achieve successful control.

While these strategies are effective, they are limited in efficiency (typically controlled on average between 30% and 50%).

Accordingly, there is a need for improved medical devices and methods for managing the progression or axial length increase of refractive errors.

Disclosure of Invention

According to a first broad aspect, there is provided a medical device for managing axial length growth of an eye of a subject, the eye having a pupil, the device comprising: a central region having a first degree; a transition zone surrounding the central zone and having a width equal to 1.5mm at the most; and a peripheral region surrounding the transition region, the peripheral region having a second degree, wherein the surface area of each of the central region and the peripheral region is selected as a function of the surface area of the pupil of the eye.

In one embodiment, the surface area of the pupil of the eye corresponds to the surface area of the pupil of the eye evaluated under photopic conditions when the subject looks away with the naked eye.

In an embodiment, the central and peripheral regions are adapted to treat at least one of myopia and astigmatism.

In one embodiment, the surface area of the central region and the transition region is about 20% to about 40% of the surface area of the pupil of the eye.

In one embodiment, the first power of the central zone is about-0.25 diopters to about-30 diopters for near vision and about-0.25 diopters to about-10 diopters for astigmatism.

In one embodiment, the second degree of the peripheral region is determined based on the target net degree and the first degree of the central region.

In one embodiment, the target net power is about +3.5 diopters to about +10 diopters, and the second power is about +3.75 diopters to about +20 diopters.

In one embodiment, the target net power is equal to about +5 diopters.

In another embodiment, the central and peripheral regions are adapted to treat hyperopia.

In one embodiment, the surface area of the central region and the transition region is about 30% to about 50% of the surface area of the pupil of the eye.

In one embodiment, the first power of the central zone is about +0.25 diopters to about +25 diopters.

In one embodiment, the target net power is about-3.5 diopters to about-10 diopters and the second power of the peripheral region is about-3.75 diopters to-20 diopters.

In one embodiment, the target net power of the peripheral zone is equal to about-5 diopters.

In yet another embodiment, the central and peripheral regions are adapted to treat presbyopia.

In one embodiment, the medical device corresponds to a remote central device.

In one embodiment, the surface area of the central portion and the transition portion is about 20% to about 30% of the surface area of the pupil of the eye.

In one embodiment, the first power of the central zone is about-30 diopters to about +25 diopters.

In one embodiment, the peripheral region is provided with an add power of about +0.25 diopters to about +5 diopters.

In one embodiment, the add power of the peripheral region is equal to about +2.5 diopters.

In another embodiment, the medical device corresponds to a near-central device.

In one embodiment, the surface area of the central portion and the transition portion is about 10% to about 30% of the surface area of the pupil of the eye.

In one embodiment, the second power of the peripheral region is about-30 diopters to +25 diopters.

In one embodiment, the central zone is provided with an add power of about +0.25 diopters to about +5 diopters.

In one embodiment, the add power of the central zone is equal to about +2.5 diopters.

In one embodiment, the second degree is constant throughout the peripheral region.

In another embodiment, the peripheral region includes a plurality of angular portions, each angular portion having a respective degree.

In one embodiment, two adjacent corner portions of the plurality of corner portions are provided with different degrees.

In one embodiment, the respective degree is equal to one of a first degree of the central region and a second degree of the peripheral region.

In one embodiment, the medical device further comprises an outer region surrounding the peripheral region.

In one embodiment, the medical device further comprises a transition region between the peripheral region and the outer region, the transition region having a width equal to about 1.5mm at the most.

In one embodiment, the outer region includes a plurality of angular portions, each angular portion having a respective degree.

In one embodiment, the outer area is divided into an even number of said corner portions.

In one embodiment, the medical device is a corrective lens.

In one embodiment, the corrective lens is a contact lens.

In one embodiment, the contact lens is a soft contact lens.

In another embodiment, the contact lens is one of a rigid lens, a gas permeable lens, and a hybrid lens.

In one embodiment, the corrective lens is an intraocular lens.

According to another broad aspect, there is provided a method for treating an eye condition in a subject, the method comprising: determining refractive error of the eye of the subject; determining a surface area of a pupil of an eye; and to provide the medical device described above.

According to yet another broad aspect, there is provided a medical device for managing axial length growth of an eye of a myopic subject, the eye having a pupil, the device comprising: a central region having a first power for accommodating distance vision; a transition zone surrounding the central zone and having a width equal to 1.5mm at the most; and a peripheral zone surrounding the transition zone, the peripheral zone having a second power, wherein the surface area of the central zone and the transition zone is about 20% to about 40% of the surface area of the pupil of the eye, and wherein the first power of the central zone is about-0.25 diopters to about-30 diopters.

In one embodiment, the surface area of the pupil of the eye when the subject looks away with the naked eye corresponds to the surface area of the pupil of the eye evaluated under photopic conditions.

In one embodiment, the target net power is equal to about +5 diopters.

In one embodiment, the medical device is a corrective lens.

In one embodiment, the corrective lens is a contact lens.

In one embodiment, the contact lens is a soft contact lens.

In one embodiment, the corrective lens is an intraocular lens.

According to yet another broad aspect, there is provided a method for treating an eye condition in a subject, the method comprising: determining refractive error of the eye of the subject; determining the surface area of the pupil of the eye; and to provide the medical device described above.

According to yet another broad aspect, there is provided a method for managing axial length growth of an eye of a subject, the method comprising: creating a central region within a cornea of an eye of a subject, the central region having a first degree; creating an intermediate zone within the cornea of the eye surrounding the central zone, the intermediate zone having a width at most equal to about 1.5 mm; and creating a peripheral region within the cornea of the eye surrounding the intermediate region, the peripheral region having a second degree, wherein the surface area of each of the central region and the peripheral region is selected as a function of the surface area of the pupil of the eye.

In one embodiment, the step of creating the central, intermediate and peripheral regions comprises propagating a laser beam on the cornea of the eye.

In one embodiment, the central and peripheral regions are adapted to treat at least one of myopia and astigmatism.

In one embodiment, the first power of the central zone is about-0.25 diopters to about-30 diopters for near vision and about-0.258 diopters to about-10 diopters for astigmatism.

In one embodiment, the target net power is equal to about +5 diopters.

In another embodiment, the creating the peripheral region includes creating a plurality of corner portions within the peripheral region, each corner portion of the plurality of corner portions having a respective degree.

In one embodiment, the method further comprises the step of creating an outer zone surrounding the peripheral zone.

In one embodiment, the method further comprises the step of creating a transition region between the peripheral region and the outer region, the transition region having a width equal to about 1.5mm at the most.

In the following, it will be understood that a first power, expressed in diopters, is associated with the central zone and a second and different power, also expressed in diopters, is associated with the peripheral zone.

The number of degrees in the central zone is the number of degrees equal to the subject's telerefractive error.

The degrees of the peripheral region refer to the degrees of the degrees added to the central region. The degrees of the peripheral region may be selected to achieve a target net degree determined to be effective in controlling myopia progression or axial length growth in a given subject. In the case of hyperopic subjects, the power of the peripheral zone is similar to the addition power.

The net power number refers to the sum of the power of the central region and the power of the peripheral region.

The net power may be referred to as net positive power when it corresponds to an increase in the convexity of the peripheral zone, which is higher than the negative power of the central zone in the case of lenses designed to control myopia/astigmatism and/or axial length.

The clarity number may be referred to as net negative when it corresponds to an increase in the amount of concavity in the peripheral zone, which is higher than the positive in the central zone in the case of lenses designed to control distance vision and/or axial length.

The addition power means that, in the case of a lens designed to correct hyperopia, the convexity power is increased in the peripheral region, regardless of whether the central region is provided with a positive power or a negative power.

The peripheral region may be designed according to a target degree or a target net degree. When the target net number is set for the peripheral region, the number of degrees of the peripheral region is obtained by subtracting the number of degrees of the central region from the net number of the peripheral region.

In the following, the values of the power related to astigmatism are expressed as negative numbers according to the optometric standard. However, those skilled in the art will appreciate that positive values should be used for degrees if compliance with the ophthalmology standards is desired.

Drawings

Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which:

fig. 1 shows a medical device for treating refractive error according to an embodiment, the medical device comprising a central zone, a middle zone and a peripheral zone, the medical device having a surface area equal to the surface area of the pupil;

FIG. 2 shows a medical device for treating refractive error according to an embodiment, the medical device comprising a central zone, a medial zone and a peripheral zone, the medical device having a surface area greater than a surface area of a pupil;

fig. 3 shows a medical device for treating refractive error according to an embodiment, the medical device comprising a central zone, a middle zone, a peripheral zone and an outer zone; and

FIG. 4 is a flow diagram of a medical method for treating refractive error according to an embodiment;

it will be noted that throughout the drawings, like features are identified by like reference numerals.

Detailed Description

In the following, a medical device for managing axial length growth of an eye, a medical treatment method for managing axial length growth of an eye and a method for selecting an appropriate medical device for managing axial length growth of an eye are described. The medical devices and methods may be used to treat refractive errors, such as myopia, hyperopia, astigmatism, and/or presbyopia.

The inventors found that it is important to focus first on the development of the axial length of the eye as a response to multifactorial stimuli such as peripheral refraction. In fact, as it grows, the eye becomes elongated and the lens, which is usually present inside the eye, changes its shape, and the volumes of the anterior and posterior chambers may also change to accommodate this elongation. This process is called emmetropization. For subjects with myopia, or hyperopic subjects, this emmetropization process no longer functions normally as if the biofeedback between the retina and other structures of the eye appears to disappear, alter, or break down. Thus, according to the present inventors, myopia should be considered a clinically measurable effect of axial length extension without effective emmetropization. Furthermore, myopia can be considered a significant risk factor for the development of ocular lesions when it reaches-6 diopters or axial lengths above 26 mm.

Most of the prior art for managing myopia focuses on myopia progression, i.e. change in diopter over time, without taking into account the underlying pathogenic mechanism, which is a change in the length of the eye axis, not compensated by a change in the shape and/or power of the lens. Thus, according to the inventors, a device or method for managing myopia should be effective to manage first the axial length development of the eye and then the progression of refractive error.

Analysis of the corneal surface by topographic analysis shows that in the case of myopia and/or astigmatism, the Ortho-K lens flattens the central cornea with positive hydraulic pressure from the compressed tear film under the lens. This defines a region a, surrounded by a steeper region created by negative fluid pressure on the epithelial cells, referred to as region B. Zone a helps compensate for refractive error. For example, if it flattens, zone a will compensate for myopia and astigmatism to a certain extent, which is limited by the shape of the cornea. In contrast, zone B is associated with a more convex power, with a ratio to zone a of 1 to 1.25, or higher if the lens curvature is customized. The degree of the second region is defined as the net convexity (+) degree. The additional degrees of the system represent the difference between the central and peripheral regions. For example, given a cornea with a central curvature of 45 diopters, a standard Ortho-K lens that produces 3 flattening diopters would have zone a at 42 diopters and zone B at 49 diopters. In power, this change is associated with a central-3 diopter effect and +4 diopters of the B zone. The add power of this system was then evaluated at 7 diopters. Clinical results indicate that the amount of convexity and the area to which the net normal number is achieved in the peripheral retina will affect the manner in which myopia and axial length develop. If a large transition region is inserted between region a and region B, the degree transition between them may be slow. It may also be abrupt, meaning that the transition is very rapid, with a steep slope between the degrees produced in region a and the degrees produced in region B. In the first case, the slower transition may be used as an optical correction (40 to 80 cm) or a balance adjustment for the intermediate distance. In the second case, the fast transition is still noisy for the brain and cannot be used for optical correction.

The inventors have found that using a higher net positive number of degrees, and defining a balance between the diameters of regions a and B based on the pupil area, and an abrupt and rapid transition between the degrees of regions a and B, indicates better results.

The inventors have also found that the low add power of soft multifocal lenses is less effective in controlling myopia and axial length progression, especially in situations where binocular vision is an issue. They found that the use of higher convexity values for the B region is generally associated with distance blur in current commercial designs, creating the need for over-correction of the patient, which may affect accommodation and convergence. For some lenses provided with high add power, the lens center is also more problematic and decentration can change the result due to misalignment of the lens area and the eye's visual axis.

As a result, the inventors have developed a medical device suitable for managing the axial length of the eye to treat refractive errors (e.g., myopia and hyperopia) whether or not astigmatic. Based on the same principle, but by adjusting the degree, the device can also be used to correct presbyopia without affecting the axial length. The medical device is adapted to be worn by a subject or user. For example, the medical device may be worn directly on the surface of the ocular surface of the subject. The medical device comprises three segments or portions, namely a central portion, an intermediate or transition portion and a peripheral portion. The power of the lens or the power of the central portion is selected in accordance with the refractive error to be treated so as to adjust the distance vision of the subject's eye without producing central blur. The peripheral portion exhibits a different power relative to the central portion and is adapted to affect a peripheral refraction. In one embodiment, the degree value remains substantially constant throughout the peripheral portion. This means that the degree of the peripheral portion varies relative to the degree of the central portion. For example, for a net positive power of +5 diopters, the power of the peripheral zone is +8 diopters considering the power of-3 diopters of the central zone, but if the central zone power is equal to-3.5 diopters, the power of the peripheral zone is +8.5 diopters. In one embodiment, the sum of the central zone degree and the peripheral zone degree corresponds to a predetermined number, referred to as the net degree of the peripheral zone or the net positive degree when it is positive. In one embodiment, the net positive power is +2 diopters to +20 diopters. In the case of hyperopia, the net power is negative and is referred to as net negative power. In one embodiment, the net negative power is between-2 diopters and-20 diopters. For example, if the net negative power is set to-6 diopters, a given lens can be designed for a central zone power of +4 diopters and a peripheral zone power of-10 diopters. If the power of the central zone is changed to +5 diopters, the power of the peripheral zone will be set to-11 diopters.

In both near and far vision situations, the peripheral zone power values should be chosen so as not to interfere with the natural accommodation process. Thus, the net power in the peripheral zone should exceed 3.5 diopters, i.e., +3.5 diopters for near vision and-3.5 diopters for distance vision. In the case of hyperopia, the peripheral zone power value can be considered as an additional value to the distance power and is selected to correct near vision. In this case, the net power of the peripheral area may be from +0.5 diopter to +5 diopter. The surface areas of the three regions are selected according to the pupil surface area, and the width of the intermediate portion is selected such that the degree transition between the central and peripheral portions occurs abruptly.

In the case of myopia, the inventors found that indicating the smaller diameter of the central zone (zone a) in combination with the larger diameter of the surrounding zone (zone B) for a fast progressor (>0.75 diopters/year) because such subjects required a larger area of net positive power in the optical system to obtain better control. Furthermore, a larger diameter central zone is indicated when myopia or axial length tends to stabilize, or if the viewing distance is too great to affect the wearing of a lens designed with a smaller diameter central zone. Thus, in the case of myopia, the surface area of the portion including the central and intermediate regions should be 20% to 40% of the total pupil area.

In the case of distance vision, the same reasoning may apply, except that a larger central region is required to mitigate distance blur. Therefore, the surface area of the portion including the central region and the intermediate region should be 30% to 50% of the entire pupil area.

In both cases, the transition should not produce an optically usable degree of the vision system. This means that the progression from the central region to the peripheral region should be rapid and abrupt, and the slope of the degree curve should be as steep as possible in the middle region. This also means that the width of the intermediate region should be kept as small as possible. In one embodiment, the width of the middle region should be less than 1.5 mm. For example, the width of the intermediate region may be about 0.1mm to about 1.5 mm.

The width of the peripheral zone is determined by the overall optical zone diameter of the lens. Typically, the optical zone diameter of the lens varies between about 6mm to 8mm depending on the lens design, material, overall diameter of the lens, power of the lens, and the corrective objective of the device.

Thus, the medical device may be designed as follows:

the width of the optical zone of the lens is equal to the central zone width + the intermediate zone width + the peripheral zone width.

For example, given an optical zone of about 8.0mm, the width of the central zone may be equal to about 2.2mm, the width of the middle zone may be equal to about 0.5mm, and the width of the periphery may be equal to about 5.3 mm. In another example of high myopia, and given an optical zone of about 6mm, the width of the central zone may be equal to about 2.27mm, the width of the intermediate zone may be equal to about 1mm, and the width of the peripheral zone may be equal to about 2.73mm, with add powers in excess of +10 diopters.

In one embodiment, the medical device is a corrective lens adapted to treat myopia or hyperopia or presbyopia with or without astigmatism. The corrective lenses may be contact lenses (e.g., soft or hard), gas permeable lenses, or hybrid lenses. Hybrid lenses are defined as contact lenses that are rigid or rigid gas permeable in the center and surrounded by a soft support skirt. The skirt may be made of hydrogel, silicone hydrogel or any other approved material, and the hybrid lens may be manufactured as a single unit. In another embodiment, the corrective lens may also be an intraocular lens.

FIG. 1 illustrates one embodiment of a medical device 100 for managing axial length growth of an eye 102. The eye 102 includes a pupil 104, a cornea 105, an iris (not shown), and a sclera 106. At least the pupil 104 and the visible iris are covered by the cornea 105.

The medical device 100 is adapted to be centered over the cornea 105 and more precisely in front of at least the geometric center of the pupil 104. In one embodiment, once positioned, the medical device 100 may be in physical contact with the ocular surface (i.e., the surface of the eye 102).

The medical device 100 includes a central region 110, a middle region 112, and a peripheral region 114. The central region 110 is substantially circular, while the intermediate and peripheral regions 112 and 114, respectively, have an annular shape. A central region 112 extends radially from the central region 110 along a first width, and a peripheral region 114 extends from the central region 112 along a second, different width. Once the medical device is mounted on the subject, the center of the central portion 110 and the center of the pupil 104 overlap with each other such that the medical device 100 is centered on the pupil 104. In one embodiment, best fit means that the optical axis of the medical device coincides with the visual axis of the eye, which may be slightly different from the geometric center.

The power of the central zone 110 is selected to adjust the distance vision of the subject according to the type of refractive error to be treated and the characteristics of the subject. The power of the peripheral region 114 is selected to affect peripheral refraction (myopia and hyperopia) or to correct near vision (presbyopia). When the medical device 100 is adapted to handle myopia, the peripheral region 114 provides a degree value that is more convex than the degree value of the central region. When the medical device 100 is adapted to handle distance vision, the peripheral region 114 provides more concave power values than the central region. The middle region 112 has no effective degree but facilitates the transition between the distance and the peripheral region. The surface changes rapidly from the degree value of the central region 110 to the degree value of the peripheral region 114. The width of the middle region 112 is selected so that the transition between distance and peripheral degrees changes abruptly and the degree profile has a slope as steep as possible and a width as small as possible. In one embodiment, the width of the middle region 112 is equal to or less than 1.5 mm.

In one embodiment, if the power of the central zone is negative and used for myopia and/or astigmatism control, the power of the peripheral zone 114 is +3.75 diopters to +20 diopters.

In another embodiment, if the central zone power is positive and used for distance vision control, the peripheral zone 114 power is between-3.75 diopters and-20 diopters. In one embodiment, such degree values of the peripheral region 114 (associated with a minimum width of about 0.1mm to a maximum width of about 1.5mm of the middle region 112) ensure abrupt degree changes between the central region 110 and the peripheral region 114.

Presbyopic patients typically have a smaller pupil that narrows even more when read or viewed at close distances. Thus, for distance vision, a smaller central zone should be designed to provide a larger peripheral zone and a larger zone of add power in the system for presbyopia correction. Another reason is that when the design is used for presbyopia, the purpose is not to change the axial length, nor to change the progression of refractive error over time. Thus, the balance between distance and near power and their relative areas should be different compared to near or far vision management.

Thus, to correct presbyopia, and in a design known as distance center, the powers of the peripheral zone 114 are selected so that the peripheral zone 114 provides an add power of +0.25 diopters to +5 diopters (relative to the power of the central zone 110), which is a common add power common to mature presbyopia. For certain very precise tasks at close distances, additional degree values above +3.00 may be required. For example, a person requiring precise vision at 20 cm may require an add power value of +5 diopters. The area of the central region may be 20% to 30% of the pupil area. Alternatively, in a design referred to as near center, the power of the central zone may be selected such that the add power provided by the central zone 110 (relative to the power of the peripheral zone 114) may be +0.25 diopters to +5 diopters.

In the illustrated embodiment, the three regions 110, 112, and 114 of the medical device 100 are located wholly or partially over the pupil 104 such that the medical device 100 may overlap the pupil 104 once the medical device has been installed on a subject. The surface areas of the different regions 110, 112 and 114 of the medical device 100 are selected according to the surface area of the pupil 104 of the eye 102 to be treated. In one embodiment, the surface area of the pupil is evaluated using electronic or manual means in photopic conditions, as is known in the art, with the patient gazing far away and the eye not covered. The surface area of each region 110, 112, 114 is selected so as to cover a given percentage of the surface area of the pupil 104 when the medical device 100 is installed on a subject (i.e., when the medical device 100 is installed on the subject's eye 102). The percentage of the surface area of the pupil 104 that each zone 110, 112, 114 covers, the powers of the central zone 110 and the powers of the peripheral zone 114 (so long as the peripheral zone powers range from about +3.75 diopters to about +20 diopters for near vision; from about-3.75 diopters to about-20 diopters for far vision; and from +0.25 diopters to +5 diopters for presbyopic eyes) are selected according to the refractive error of the subject to be treated, its evolution over time, and/or some characteristic (e.g., the size (diameter) of the subject's pupil 104 and the diopters of the subject's eye). For any refractive error and any subject, the power of the peripheral zone 114 is about +3.75 diopters to about +20 diopters (myopic), about-3.75 diopters to about-20 diopters (hyperopic) or is selected such that the added value of the peripheral zone 114 is +0.25 diopters to about +5.00 diopters (presbyopia), and the width of the intermediate zone 112 is selected to be at most equal to 1.5mm to ensure an abrupt power change between the central zone 110 and the peripheral zone 114.

While the present medical device can be fully customized for each subject based on individual parameters, a more practical choice can be provided by an average customization process. More precisely, the inventors have determined after studying various populations that for myopic subjects showing a pupil diameter of about 4mm to about 5mm, the central zone will be about 5.02mm²Whereas a subject with a pupil diameter of about 5.1mm to about 6.4mm will first fit about 8.19mm²And finally, if the subject's pupil diameter is at least equal to about 6.5mm, the area of the central zone is about 13.27mm in the first intention²。

While the diameter of the pupil is estimated when the patient gazes far away under photopic conditions, it should be understood that other methods for determining the pupil diameter may be used. For example, the diameter of the pupil may be measured under dim lighting conditions. In this case, a correction factor is applied to the measured pupil diameter to obtain the pupil diameter measured under photopic conditions when the patient is gazing far away. Similarly, if the diameter of the pupil is measured under bright lighting conditions, a correction factor may be applied to the measured pupil diameter to obtain the diameter of the pupil measured under photopic conditions when the patient gazes far away.

In one embodiment, the refractive error to be treated is myopia. In this case, the rate of increase in the eye axis length is reduced. The surface area of the portion comprising central region 110 and intermediate region 112 is selected to be about 20% to about 40% of the surface area of pupil 104 of eye 102. As a result, the surface area of the peripheral region 114 is about 60% to about 80% of the surface area of the pupil 104. The central zone 110 has a power of-0.25 diopters to-30 diopters. The peripheral zone 114 has power in the range of about +3.75 diopters to about +20 diopters to achieve a net power in the peripheral zone of about +3.5 diopters to about +10 diopters regardless of central refractive error. In one embodiment, the net positive power of the peripheral region 114 is about +5 diopters. In this case, a lens with-2 diopters of power at distance would be designed to have peripheral power of about +7 diopters. For a lens having a central zone power of about-4.00 diopters, a peripheral zone power of about +9 diopters would be required to achieve a net power of +5 diopters.

For example, for a given subject with-3.00 diopters, progressing at 0.50 diopters per year, and showing a pupil diameter of 5mm under photopic conditions, the pupil area is 19.64mm². The central zone may be from 20% (3.93 mm)²) To 40% (7.85 mm)²). In this case, the subject may be fitted with a device designed to have-3 diopters of power in the central zone to correct distance vision. The central and middle regions cover a region of 2.74mm in diameter (coverage 30%), and if desired, 3.16mm (coverage 40%). The central zone will be surrounded by a peripheral zone of net +5 diopters (peripheral power +8 diopters), the width of the central zone being 5.26mm (70% coverage), adjustable to 4.84mm (60% coverage) given a total optical zone diameter of 8mm, which can be limited if the peripheral zone has a power less than +10 diopters. Another example could be to have a subject of-8 diopters (called a fast-forwarding person) (showing a pupil diameter of 6 mm) wear a lens designed with a zone diameter of 2.68mm (20%) covered by a central zone and a middle zone, and a peripheral zone with a net power of +5 diopters (i.e., peripheral power of +11 diopters), and a width of the peripheral zone of 4.72mm (considering a total optical zone diameter of 8mm) (because of the higher added value).

In embodiments where the refractive error to be treated is hyperopia, the rate of growth of the axial length of the eye will be increased. The surface area of the portion comprising the central region 110 and the intermediate region 112 is selected to be about 30% to about 50% of the surface area of the pupil 104 of the eye 102. As a result, the surface area of the peripheral region 114 is about 50% to about 70% of the surface area of the pupil 104. The power of the central area 110 is +0.25 diopters to +25 diopters. The peripheral zone 114 has a power of about-3.75 diopters to about-20 diopters to achieve a smaller convexity or greater concavity value to the peripheral retina regardless of central refractive error. The net minus power of the peripheral zone 114 is about-3.5 diopters to about-10 diopters. In one embodiment, the net minus power of the peripheral region 114 is about-5 diopters. For example, if the constant net power is set to-5 diopters, a lens with +2 diopters of power (i.e., a central zone of +2 diopters of power) at distance is designed with-7 diopters of peripheral power. Another lens at distance +4 diopters would have to have-9 diopters of peripheral power to achieve the same net power value at-5 diopters.

The inventors have found that in the case of distance vision control, and if the area of the central zone is less than 30% of the pupil area, distance vision may be significantly affected. They also found that the central region exceeded 50% of the pupil area and the peripheral region had insufficient effect. Given a patient of +4 diopters, with a 4.5mm pupil, the subject can fit the lens with +4 diopters for the central zone, a width of 2.46mm (30%) for the area covering the central and intermediate zones (considering an 8mm optical zone), and a peripheral zone net power of-3 diopters (i.e., -7 diopters of peripheral zone power), with a width of 6.04 mm.

In embodiments in which the refractive error to be treated is astigmatism, the surface area of the portion comprising central zone 110 and intermediate zone 112 is selected to be about 20% to about 40% of the surface area of the pupil 104 of the eye 102. As a result, the surface area of the peripheral region 114 is about 60% to about 80% of the surface area of the pupil 104. The central zone 110 has an astigmatism of-0.25 diopters to-10 diopters with or without myopia or hyperopia. The peripheral zone 114 has power of about +3.75 diopters to about +20 diopters to achieve a net power of from +3.5 diopters to +10 diopters regardless of central refractive error. In one embodiment, the net positive power of the peripheral region 114 is about +5 diopters. For example, in the case of astigmatism, if a constant net power is set to +5 diopters, a lens with a distance power of-2 diopters will be designed with a peripheral zone power of +7 diopters. Another lens with a central toric power of-4 diopters must carry a peripheral zone toric power of +9 diopters to achieve the same net positive value of +5 diopters.

In a first embodiment, where a far-central design is used to treat ametropic presbyopia, the central zone 110 may be used to correct distance vision. In this case, the surface area of the portion comprising the central region 110 and the intermediate region 112 is selected to be about 20% to about 30% of the surface area of the pupil 104 of the eye 102. As a result, the surface area of the peripheral region 114 is about 70% to about 80% of the surface area of the pupil 104. The central zone 110 has a power of-30 diopters to +25 diopters. The power of the peripheral zone 114 is selected such that the peripheral zone 114 provides an add power of about +0.25 diopters to about +5 diopters, i.e., the power of the peripheral zone 114 is about +0.25 diopters to about +5 diopters. In one embodiment, the add power of the peripheral region 114 is about +2.5 diopters.

In a second embodiment, in which a near-center design is used to treat hyperopia for refractive errors, the peripheral region 114 is used to correct distance vision. In this case, the surface area of the portion comprising the central region 110 and the intermediate region 112 is selected to be about 10% to about 30% of the surface area of the pupil 104 of the eye 102. As a result, the surface area of the peripheral region 114 is about 70% to about 90% of the surface area of the pupil 104. The peripheral region 114 has a power of-30 diopters to +25 diopters. The power of the central zone 110 is selected such that the central zone 110 provides an add power of about +0.25 diopters to about +5 diopters. In one embodiment, the add power of the central zone 114 is about +2.5 diopters.

Although in the embodiment shown in fig. 1, the sum of the surface areas of the three regions 110, 112, and 114 is substantially equal to the surface area of the photopic pupil 104, it should be understood that other configurations are possible. For example, the total surface of these three zones may be greater than the total surface of the pupil, as shown in FIG. 2.

Fig. 2 shows a medical device 200 for treating refractive error by managing the ocular axial length of an eye 202. In this embodiment, the width (or diameter) of the medical device 200 is greater than the diameter of the cornea 205.

The medical device 200 is adapted to be positioned in front of the eye 202, and more precisely at least in front of the pupil 204. In one embodiment, once positioned, the medical device 200 may be in physical contact with the ocular surface of the eye 202.

The medical device 200 includes a central region 210, a middle region 212, and a peripheral region 214. The central region 210 is substantially circular, while the intermediate region 212 and the peripheral region 214 each have an annular shape. The central region 212 extends radially from the central region 210 along a first width, and the peripheral region 214 extends from the central region 212 along a second and different width. In this embodiment, the total radius of the medical device 200 corresponds to the sum of the radius of the central region 210, the width of the intermediate region 212, and the width of the peripheral region 214, the total radius being greater than the radius of the pupil 204. As a result, the surface area of the medical device 200 is greater than the surface area of the pupil 204.

The power of the central zone 210 is selected to adjust the subject's distance vision according to the type and characteristics of the refractive error to be treated by the subject. The power of the peripheral region 214 is selected to affect peripheral refraction in the case of myopic and hyperopic subjects. In the case of hyperopic subjects, the power of peripheral vision is selected to correct near vision and not affect axial length. The degree transition in the middle zone 212 varies rapidly from the degree values in the central zone 210 to the degree values in the peripheral zone 214. The slope of the degree transition should be as steep as possible. The width of the middle region 212 should be minimal and selected along with the value of the degrees of the peripheral region 214 such that the change in degrees within the middle region 212 is rapid and abrupt. In one embodiment, the width of the middle region 212 varies between about 0.1mm to about 1.5mm depending on the degree of the peripheral region. It is technically possible that powers above +10 diopters require a larger transition zone, while any powers below +10 diopters need to be as small as possible.

The surface area of each region 210, 212, 214 of the medical device 200 is selected according to the surface area of the pupil 204 of the eye 202 to be treated. The surface area of each region 210, 212, 214 is selected to cover a given percentage of the surface area of the photopic pupil 204 when the medical device 200 is installed on a subject (e.g., when the medical device 200 is installed on the subject's eye 202). For example, the area 210 may vary between 2mm to 4.2 mm; the area 212 may vary between 0.1mm and 1.5mm and the peripheral area 214 may vary between 2.6mm and 6mm (allowing for an optical area of 8 mm). The percentage of the surface area of the pupil 204 that each zone 210, 212, 214 covers, the power of the central zone 210, and the power of the peripheral zone 214 (provided that the power of the peripheral zone 214 is about +3.75 diopters to about +20 diopters for near vision with or without astigmatism, or about-3.75 diopters to about-20 diopters for far vision with or without astigmatism, or is selected such that the central zone 110 or the peripheral zone 214 provides 0.25 to +5.00 diopters of add power for presbyopia with or without astigmatism) are selected according to the refractive error to be treated and some characteristic of the subject (e.g., the diameter of the subject's pupil 204 and the refraction of the subject's eye). The degree of the peripheral region 214 is selected to provide a fixed net value and depends on the degree of the central region 201. For any refractive error and any subject, the power of the peripheral zone 214 is about +3.75 diopters to about +20 diopters (myopia with or without astigmatism) or about-3.75 diopters to about-20 diopters (hyperopia with or without astigmatism) or the add power provided by the central or peripheral zone is about +0.25 to about +5.00D (presbyopia with or without astigmatism), and the width of the intermediate zone 212 is selected to be at most equal to 1.5mm to ensure an abrupt change in power between the central zone 210 and the peripheral zone 214.

In one embodiment, the refractive error to be treated is myopia. In this case, the rate of increase in the eye axis length should be reduced. In this case, the surface area of the portion comprising central region 210 and intermediate region 212 is selected to be about 20% to about 40% of the surface area of pupil 204 of eye 202. Once the medical device 200 is installed on the subject, about 60% to about 80% of the surface area of the pupil 204 is covered by the peripheral region 214. The peripheral zone 214 has a power of about +3.75 diopters to about +20 diopters and is determined from the power of the central zone to obtain a target net power to be determined. In one embodiment, the net power of the peripheral zone 214 is about +5 diopters. In this embodiment, if the power of the central zone is-3 diopters, the power of the peripheral zone is +8 diopters. If the power of the central zone is-6 diopters, the power of the peripheral zone 214 will be set to +11 diopters.

In an embodiment, the refractive error to be treated is hyperopia. In this case, the rate of increase in the eye axis length will increase. The surface area of the portion comprising central region 210 and intermediate region 212 is selected to be about 30% to about 50% of the surface area of pupil 204 of eye 202. As a result, the surface area of the peripheral region 214 is about 50% to about 70% of the surface area of the pupil 204. The power of the central zone 210 is +0.25 diopters to +25 diopters. The peripheral zone 214 has a power of about-3.75 diopters to about-20 diopters and is determined from the power of the central zone to obtain a target net power value of about-3.75 diopters to about-10 diopters. The net minus power of the peripheral zone 114 is about-3.5 diopters to about-10 diopters. In one embodiment, the net minus power of the peripheral zone 214 is about-5 diopters. In this embodiment, if the power of the central zone is +3 diopters, the power of the peripheral zone is-8 diopters. If the power of the central zone is +6 diopters, the power of the peripheral zone 214 is-11 diopters.

In one embodiment, the refractive error to be treated is astigmatism in addition to myopia or hyperopia. The surface area of the portion comprising central zone 210 and intermediate zone 212 is selected to be about 20% to about 40% of the surface area of pupil 204 of eye 202. As a result, the surface area of the peripheral region 214 is about 60% to about 80% of the surface area of the pupil 204. The central zone 210 has an astigmatism of-0.25 diopters to-10 diopters. For myopic astigmatic subjects, the peripheral zone 214 has a power of about +3.75 diopters to about +20 diopters, while for hyperopic astigmatic subjects, the peripheral zone 214 has a power of about-3.75 diopters to about-20 diopters. In one embodiment, the net positive power of the peripheral zone 214 is about +5 diopters.

In a first embodiment, where the refractive error to be treated is presbyopia, the central zone 210 may be used to correct distance vision. In this case, the surface area of the portion comprising central region 210 and intermediate region 212 is selected to be about 20% to about 30% of the surface area of pupil 204 of eye 202 for a far-center design. As a result, the surface area of the peripheral region 214 is about 70% to about 80% of the surface area of the pupil 204. The power of the central zone 210 is-30 diopters to +25 diopters. The add power of the peripheral zone 214 is about +0.25 diopters to about +5 diopters. In one embodiment, the add power of the peripheral zone 214 is about +2.5 diopters.

In a second embodiment, where the refractive error to be treated is presbyopia, the peripheral zone 214 is used to correct distance vision. In this case, the surface area of the portion comprising central zone 210 and intermediate zone 212 is selected to be about 10% to about 30% of the surface area of pupil 204 of eye 202 for near-distance central designs. As a result, the surface area of the peripheral region 214 is about 70% to about 90% of the surface area of the pupil 204. The peripheral zone 214 has a power of-30 diopters to +25 diopters. The power of central zone 210 is selected such that central zone 210 provides an add power of about +0.25 diopters to about +5 diopters. In one embodiment, the add power of the peripheral region 114 is about +2.5 diopters.

In one embodiment, the correction of astigmatism and the correction of myopia or hyperopia may be combined in the central zone and extended to the peripheral zone according to the above design.

In one embodiment, according to the above design, correction of astigmatism can be combined with correction of myopia or hyperopia in the central zone, but not into the peripheral zone.

In one embodiment, correction of astigmatism may be combined with correction of presbyopia in the peripheral region and/or the central region.

Higher order aberrations are known to cause a reduction in visual acuity and may also affect the development of refractive errors. Higher order aberrations may be inherent in the optical components of the eye as well as the optics of the optics intended to correct visual acuity. The medical devices described herein produce a negative spherical aberration if the degree of the central region is negative and a positive spherical aberration if it is positive.

In one embodiment, the medical device may be designed to incorporate a change in power on its anterior surface to minimize the negative effects of its optical profile on myopia and axial length development. It may also incorporate changes in the power of its anterior surface to optimize the positive effects of its optical profile on myopia and axial length management.

In one embodiment, the front surface of a medical device having a negative central zone power may be modified to reduce the negative spherical aberration produced by its central zone power.

In another embodiment, the anterior surface of the medical device having a positive central zone power may be modified to reduce the positive spherical aberration produced by its central zone power.

In another embodiment, the anterior or posterior surface of the medical device may be modified differently on each principal meridian to accommodate the presence of toric correction (for astigmatism).

In yet another embodiment, in the case of presbyopia correction, the anterior surface of the medical device may be modified to achieve a neutral level of spherical aberration caused by the central zone power.

Although the above description refers to central regions 110, 210 having a circular shape and intermediate regions 112, 212 and peripheral regions 114, 214, respectively, having an annular shape, it should be understood that the central, intermediate and peripheral regions may have other shapes. For example, they may have an oval shape, a square shape, etc., so long as each area covers the above-defined percentage of the surface area of the pupil.

In one embodiment, the medical device 100, 200 is a corrective lens.

In one embodiment, the corrective lens is a contact lens adapted to be positioned on the ocular surface of a subject. In one embodiment, the contact lens is a soft lens. In another embodiment, the contact lens is a rigid, gas permeable lens or a hybrid lens.

In another embodiment, the corrective lens is an intraocular lens.

In one embodiment, the medical device 100, 200 includes a fourth annular region 116, 216 extending radially from the peripheral region 114, 214 and surrounding the peripheral region 114, 214, respectively. The width of the fourth region 116, 216 may be selected such that the medical device 100, 200 covers at least the entire surface of the visible cornea, respectively. In embodiments where the medical device is designed for near vision, the degree of the fourth region 116, 216 may be selected to be greater than the degree of the peripheral region 114, 214. For example, the fourth zone 116, 216 may have a power that is 1.0 diopters to 10 diopters greater than the power of the peripheral zone 114, 214. In embodiments where the medical device is designed for distance vision, the degree of the fourth region 116, 216 may be selected to be less convex or more concave than the peripheral region 114, 214. For example, the fourth zone 116, 216 may have a power that is 1.0 diopters to 10 diopters less than the power of the peripheral zone 114, 214.

It should be understood that other characteristics of the medical device 100, 200, such as the curvature of the medical device, the width of the fourth region (if any), the material or materials from which the medical device 100, 200 is made, etc., may be determined according to prior art methods.

In one embodiment, the fourth region has a degree constant over the entire surface area of the fourth region.

In another embodiment, the degree is not constant in the fourth region and may vary throughout the fourth region. For example, the degree associated with the fourth region may vary depending on the angular position.

In one embodiment, the fourth region may be divided into at least two portions, each portion having a corresponding degree. FIG. 3 illustrates one embodiment of a medical device 250 for managing axial length growth of an eye. The medical device 250 includes a central region 252, a middle region 254 surrounding the central region 252, a peripheral region 256 surrounding the middle region 254, and a fourth or outer region 258 surrounding the peripheral region 256. The central region 252 is provided with a first degree and the peripheral region 256 is provided with a second, different degree. As described above, the degrees of the peripheral region 256 can be determined from the target net number using the degrees of the central region 252.

The outer region 258 is divided into four corner segments or quadrants 260 and 266, each segment having a respective degree. Quadrants 260-266 may correspond to the superior, nasal, inferior and temporal quadrants. In the case of the right eye, quadrants 260, 262, 264, and 266 may correspond to the upper, nasal, lower, and temporal quadrants, respectively. In the case of the left eye, quadrants 260, 262, 264, and 266 may correspond to the upper, temporal, lower, and nasal quadrants, respectively. In one embodiment, the degrees of the quadrants 260 and 266 alternate between the degrees of the central region 252 and the degrees of the peripheral region 256, and two adjacent quadrants 260 and 266 are provided with different degrees. For example, quadrants 260 and 264 may be provided with the same number of degrees as the central region 252, while quadrants 262 and 266 may be provided with the same number of degrees as the peripheral region 256.

Although the outer region 258 is divided into four sections 260 and 266, it should be understood that the number of corner sections may vary so long as the outer region 258 includes at least two sections. In one embodiment, the number of corner portions may be equal to an even number. For example, the number of quadrants may be four, eight, etc.

In one embodiment, the medical device 250 may further include a transition region sandwiched between the peripheral region 256 and the outer region 258. The thickness of the transition region may be selected to be as thin as possible to provide an abrupt degree transition between the peripheral region 256 and the outer region 258. In one embodiment, the width of the transition zone is at most equal to 1.5 mm.

In one embodiment, the medical device 250 may be designed with or without central plus-minus degrees of astigmatism. The outer region 258 may have a higher or lower net power (for near vision) and various net powers (for far vision) in each of the four corner portions or quadrants. The angle portions may be regrouped by pairs, and each pair of angle portions may have the same degree. For example, the nasal and temporal quadrants may have the same first degree, while the upper and lower quadrants may have the same second degree that is different from the first degree.

In one embodiment, the surface area of the area covered by the peripheral region 256, the outer region 258, and optionally the transition region (if any) between the peripheral region 256 and the outer region 258 corresponds to the percentage of the pupil associated with the peripheral region 116, 216 described above, depending on the condition to be treated.

In one embodiment, the width of the peripheral region 256 is selected to be minimal, for example, about 0.1mm to about 1.5 mm.

Although the medical device 100, 200 includes a peripheral region 116, 216 having a uniform or constant degree therethrough, those skilled in the art will appreciate that the above-described concept of dividing the outer region 258 into multiple regions, each having a respective degree, may be applied to medical devices provided with three regions (i.e., a central region, a middle region, and a peripheral region), such as the medical device 100. For example, the peripheral region 116 may be divided into a plurality of angular portions or quadrants, each having a respective degree. For example, the peripheral region 116 may include four quadrants, such as the superior, nasal, inferior, and temporal quadrants.

In one embodiment, the degrees associated with each corner portion of the peripheral region 116 may be equal to the degrees of the central region 110 or the degrees of the peripheral region 116 described above, and two adjacent corner portions may have different degrees.

In one embodiment, the number of corners included in the peripheral region 116 may be equal to an even number. For example, the number of quadrants may be four, eight, etc.

Those skilled in the art will appreciate that such designs that include an outer region of varying degrees or designs that include a peripheral region of varying degrees may have intraocular applications and may also be applied to laser surgery.

For example, as described above, for myopia and/or astigmatism correction, the medical device may include a central zone, a middle zone, a peripheral zone, an outer zone, and optionally a transition zone between the peripheral zone and the outer zone. The central and intermediate regions may cover from about 20% to about 40% of the surface area of the pupil of the eye. The power of the peripheral zone may be about +3.75 diopters to about +20 diopters depending on the net power of the target and the power of the central zone. The surface is covered by a central region, and the peripheral region may correspond to the surface of the pupil. The outer zone includes an even number of alternating degree angular portions, the degrees of which are equal to the degrees of the central zone or the degrees of the peripheral zone. The width of the middle region and the width of the transition region (if any) may be 0.1mm to 1.5mm to provide an abrupt degree transition. Such a design may ensure that the percentage of peripheral defocus is stable even with an increased pupil diameter in darker conditions. Also, such a design may reduce the spherical aberration that occurs in darker conditions, thereby improving visual acuity.

For example, a patient with a photopic pupil diameter of 5.0mm may need to be designed as follows: a central region of 2.24mm diameter is surrounded by a 0.5mm annular middle region, a 1.4mm wide annular peripheral region and a 3.36mm wide outer region, including the portion having the degree of the central or peripheral region. For example, the outer region may include 8 corner portions, four of which have the same degree as the central region, the other four of which have the same degree as the peripheral region, and no adjacent portion has the same degree. This design can be applied to lenses with an optical zone of 8.0mm diameter and can provide 74% peripheral defocus even in darker conditions.

In another example, the same design may be applied for distance vision. In this case, the surface area of the central and intermediate regions is 30% to 50% of the pupil area. The peripheral zone is provided with a power of-3.75 diopters to-20 diopters.

In embodiments where the medical device 100, 200 is a soft contact lens, some parameters of the soft lens may be personalized for each subject. For example, the base curve of the lens, the overall diameter, the power of the central zone 110, 210, the percentage of the pupil covered by the peripheral zone 114, 214, and the width of the intermediate zone 112, 212 may be adjusted for each patient. Other parameters may not differ from subject to subject. For example, the type of lens, the net power determined to control myopia and axial length development, the optical zone diameter (i.e., the diameter of the portion comprising the central, intermediate, and peripheral zones), the width of the intermediate zone 112, 212, the peripheral curve, the material or materials from which the medical device 100, 200 is made, etc., may be constant from one subject to another.

In examples where the lens is designed to treat myopia, the base curvature may be determined based on an effective curvature reading of the subject's cornea and a flattening factor related to the final lens diameter. If the lens includes a myopia management strategy portion, the base curvature may be made steeper by 0.1mm to optimize its centration and its stability. In one embodiment, the curvature and diameter of the medical device 100, 200 are adjusted to produce a sagittal depth arch at a sagittal height of a given ocular surface, with values from about 100 microns (um) up to about 300 microns (um).

The overall diameter of the lens may be established about 2mm above the visible corneal horizontal diameter as measured by topography, bioassay, or any other suitable optical method. The power of the central region 110, 210 may be determined based on the cycloplegic refraction of the subject's eye or other valuable means of assessing the refractive component. The percentage of the pupil that will be covered by the peripheral region 114, 214 may be determined as a function of each subject's growth affecting peripheral defocus and thus affecting axial length of the eye. As described below, a range of medical devices may be designed, depending on the patient's parameters, in which the percentage of the pupil to be occluded is varied.

In examples where the lens is designed to treat myopia, the type of lens may be a bifocal soft contact lens in the far center. The net power may be equal to +5.00 diopters regardless of the subject. The optical zone diameter (i.e., the diameter of the zone including the central, intermediate and peripheral zones) can be fixed at 8mm regardless of the subject. The width of the intermediate region 112, 212 may be fixed at 0.5mm regardless of the subject, and the intermediate region 112, 212 may be designed to have a steep, fast, and abrupt degree transition, where the degree slope may be steepest. The peripheral curve from the end of the peripheral region to the edge of the medical device may be selected to be standard to facilitate lens centering and tear exchange. Finally, in the case of soft lenses, the lenses can be made of hydrogel or silicone hydrogel or any new material approved for such use, either disposable (for 1 day to 6 months) or conventional (for >6 months), regardless of the subject. The rigid lens may be made of Polymethylmethacrylate (PMMA) and the gas permeable material may be made of acrylate, silicone or fluorine (or a combination of 2 or 3 of these materials) or any new material approved for this purpose. The hybrid lens may be made from a combination of a gas permeable material and a hydrogel or silicone hydrogel or any new material approved for such use.

The medical device 100, 200 described above may be embodied as a method 300 of medical treatment of refractive errors, such as myopia, hyperopia, astigmatism or presbyopia, as shown in fig. 4.

A first step 302 includes creating a central region within a cornea of an eye of a subject. The central region is circular and centered on the pupil such that the center of the central region substantially overlaps the center of the pupil. The central region is created using a suitable energy source that modifies the shape of the cornea within the defined central region to remove a given thickness of the cornea. As described below, the surface area of the central region is selected such that the central region covers a given percentage of the surface area of the pupil. The thickness of the cornea to be removed is defined according to the desired degree of the central zone.

In one embodiment, the energy source used to alter the shape of the cornea is a laser. In another embodiment where hyperopia is to be managed, the energy source may be a heat source adapted to apply heat to the periphery of the cornea.

A second step 304 includes creating an intermediate zone within the cornea of the eye. The intermediate region has an annular shape and extends radially from the central region while surrounding the central region. An energy source is used to create an intermediate region of the cornea by cutting a given thickness of the cornea within the intermediate region. The surface area of the intermediate zone is selected such that the intermediate zone covers a given percentage of the surface area of the pupil.

A final step 306 includes creating a peripheral zone within the cornea of the eye. The peripheral region has an annular shape and extends radially from the intermediate region while surrounding the peripheral region. A peripheral region of the cornea is created by cutting a given thickness of the cornea within the intermediate region using an energy source such that the peripheral region is set to a desired degree. The surface area of the peripheral region is selected such that the peripheral region covers a given percentage of the surface area of the pupil.

In one embodiment, the energy sources used to generate the central, intermediate and peripheral regions at steps 302, 304 and 306 are lasers. In one embodiment, the laser is an excimer laser. In another embodiment, the laser is a femtosecond laser.

In one embodiment, the method 300 further comprises the step of removing the epithelial layer prior to performing step 302. The surface area of the removed epithelium corresponds at least to the surface area of the area covered by the central, intermediate and peripheral regions. Once the epithelial region is removed, central, medial and peripheral regions will be created. In one embodiment, an excimer laser is used to remove the epithelium and create central, intermediate and peripheral regions. Method 300 corresponds to Photorefractive Keratectomy (Photorefractive Keratectomy) when at least the epithelial layer is removed. It will be appreciated that any suitable method may be used to remove at least one layer of epithelium. For example, a microkeratome may be used to remove at least one layer of epithelium. In another example, a laser such as a femtosecond laser may be used.

In another embodiment, a flap (flap) is created and bent before performing the creation of the central, intermediate and peripheral regions once the three regions are created, the flap is placed back in its original position.

In one embodiment, the peripheral region created at step 306 extends beyond the pupil such that the end of the pupil is located below the peripheral region. In this case, the peripheral region includes a first portion overlapping the pupil and a second portion located outside the pupil. In one embodiment, the degree of the first portion may be different from the degree of the second portion, thereby providing a sufficient degree for the peripheral region.

In embodiments using lasers, central, intermediate and/or peripheral regions may be created point-by-point based on the topography of the cornea to reduce higher order aberrations.

It should be appreciated that the surgical method 300 may be used to correct myopia, hyperopia, astigmatism, and/or presbyopia.

The surface areas of the three different regions are selected according to the surface area of the photopic pupil of the eye to be treated. The surface area of each zone is selected to cover a given percentage of the surface area of the pupil. The percentage of pupil surface area covered by each zone, the degree of the central zone, and the degree of the peripheral zone are selected according to the refractive error to be treated and the characteristics of the subject (e.g., the size (diameter) of the subject's pupil and the cycloplegic refraction of the subject's eye). The power of the peripheral zone is from about +3.75 diopters to about +20 diopters or from about-3.75 diopters to about-20 diopters for any refractive error and any subject, or is selected such that the peripheral zone provides an add power of +0.25 to +5.00 diopters. Alternatively, the power of the central zone may be selected such that the central zone provides an add power of +0.25 to +5.00 diopters. Furthermore, the width of the middle area is chosen to be minimal, e.g. at most equal to 1.5mm to ensure a degree of abrupt change between the central area and the peripheral area.

In embodiments in which the refractive error to be treated is myopia, with or without astigmatism, the surface area of the portion comprising the central and intermediate zones is selected to be about 20% to about 40% of the surface area of the pupil of the eye. As a result, about 60% to about 80% of the surface area of the pupil 204 is covered by the peripheral region. The peripheral zone has a power of about +3.75 diopters to about +20 diopters such that the net power is about +5 diopters to about +10 diopters. In one embodiment, the net positive power of the peripheral region is about +5 diopters.

In embodiments where the refractive error to be treated is hyperopia with or without astigmatism, the increase in axial length of the eye will increase. The surface area of the portion comprising the central region and the intermediate region is selected to be about 30% to about 50% of the surface area of the pupil of the eye. As a result, the surface area of the peripheral region is about 50% to about 70% of the pupil surface area. The power of the central zone is +0.25 diopters to +25 diopters. The peripheral zone has a power of about-3.75 diopters to about-20 diopters. In one embodiment, the net negative power of the peripheral region is about-5 diopters.

In embodiments where the refractive error to be treated is astigmatism, the surface area of the portion comprising the central and intermediate regions is selected to be about 20% to about 40% of the surface area of the pupil of the eye. As a result, the surface area of the peripheral region is about 60% to about 80% of the pupil surface area. For the astigmatic component, the power of the central zone is-0.25 diopters to-10 diopters. The peripheral zone has a power of about +3.75 diopters to about +20 diopters such that the net power is +5 diopters to +10 diopters. In one embodiment, the net positive power of the peripheral region is about +5 diopters.

In a first embodiment, where the refractive error to be treated is presbyopia, the central zone may be used to correct distance vision. In this case, the surface area of the portion including the central region and the intermediate region is selected to be about 20% to about 30% of the surface area of the pupil of the eye. As a result, the surface area of the peripheral region is about 70% to about 80% of the surface area of the pupil. The power of the central zone is-30 diopters to +25 diopters. The add power of the peripheral zone is about +0.25 diopters to about +5 diopters. In one embodiment, the add power of the peripheral region is about +2.5 diopters.

In a second embodiment, where the refractive error to be treated is presbyopia, the peripheral zone is used to correct distance vision. In this case, the surface area of the portion including the central region and the intermediate region is selected to be about 10% to about 30% of the surface area of the pupil of the eye. As a result, the surface area of the peripheral region is about 70% to about 90% of the surface area of the pupil. The peripheral zone has a power of-30 diopters to +25 diopters. The power of the central zone is selected such that the central zone provides an add power of about +0.25 diopters to about +5 diopters. In one embodiment, the add power of the peripheral region is about +2.5 diopters.

For the medical devices 100, 200, the central region created in step 302 may have a circular shape, while the intermediate and peripheral regions created in steps 304 and 306, respectively, may have an annular shape. However, one skilled in the art will appreciate that other shapes are contemplated. For example, the different regions created by the method 300 may have an oval shape, a square shape, etc., so long as each region covers the above-defined percentage of the surface area of the pupil.

In the following, a method for designing a medical device for managing axial length growth of an eye of a subject is described. The user of the method may be an optometrist, ophthalmologist, optician, etc. The method allows the design of a medical device to be customized to a subject.

The user is presented with a set of predefined designs of medical devices. The set of predetermined designs includes at least two different partial designs for the medical device, and the user selects an appropriate partial design according to the needs of the subject for designing the medical device. It should be understood that the local design of the medical device includes only some of the features required to design the medical device. The features of the medical device that are not specified in the local design will be selected by the user according to certain characteristics of the subject.

In one embodiment, the local designs of the medical device each comprise a predefined percentage of the surface area of the pupil to be covered by the central and intermediate regions of the medical device. For example, when near vision is to be treated, there may be three local designs. In this case, the first partial design of the medical device may comprise a first value of the percentage of the pupil covered by the portion defined by the central and intermediate region, the first value being 35% to 40%. The second local design of the medical device may comprise a second value of the percentage of the pupil covered by the portion defined by the central and intermediate region, the second value being 30% to 35%. The third partial design of the medical device may comprise a third value of the percentage of the pupil covered by the portion defined by the central and intermediate zone, the third value being 20% to 30%.

In another example where hyperopia is to be treated, there may also be three partial designs. In this case, the first partial design of the medical device may comprise a first value of the percentage of the pupil covered by the portion defined by the central area and the intermediate area, the first value being 40% to 50%. The second local design of the medical device may comprise a second value of the percentage of the pupil covered by the portion defined by the central and intermediate region, the second value being 35% to 40%. The third partial design of the medical device may comprise a third value of the percentage of the pupil covered by the portion defined by the central and intermediate zone, the third value being 30% to 35%.

In another example where presbyopia is to be treated and the central region is used to correct distance vision (a far central design), there may also be two partial designs. In this case, the first partial design of the medical device may comprise a first value of the percentage of the pupil covered by the portion defined by the central area and the intermediate area, the first value being 25% to 30%. The second local design of the medical device may comprise a second value of the percentage of the pupil covered by the portion defined by the central and intermediate region, which second value is also 20% to 25%, but different from the first value.

In another example where presbyopia is to be treated and the central zone is used to correct near vision (near-central design), there may also be three partial designs. In this case, the first partial design of the medical device may comprise a first value of the percentage of the pupil covered by the portion defined by the central area and the intermediate area, the first value being 25% to 30%. The second local design of the medical device may comprise a second value of the percentage of the pupil covered by the portion defined by the central zone and the intermediate zone, the second value also being 20% to 25%. The third partial design of the medical device may comprise a third value of the percentage of the pupil covered by the portion defined by the central and intermediate zone, the third value being between 10% and 20%.

The user of the method selects an appropriate local design according to the subject, i.e. an appropriate percentage of the pupil covered by the portion comprising the central and intermediate zone according to the subject.

In one embodiment, the local design is selected by calculating the percentage of the pupil covered by the portion comprising the central and intermediate regions as follows:

square root (%) of the distance interval X pupil diameter for soft lenses; and

for a gas permeable lens, square root (%) X pupil diameter + β,

where β represents the value of the power distribution, for example, given a pupil diameter of 5.50mm, the formula for estimating 20% coverage would be given in square feet (0.2) X5.5 the result would be 2.46mm for 40% coverage, the formula being square root (0.4) X5.5 mm to 3.48mm

The choice of an appropriate local design may also be determined by the history of the progression of refractive error of the subject. Fast-forwarding may benefit from a smaller central zone (about 20%) and a higher value of clarity (> +5.00 diopters), which means a higher value of the convexity's peripheral power. More stable patients may be more suited to larger central regions and moderate peripheral values. For example, moderately developed-5 diopters of myopia may fit coverage of 30% to 40% and a net power value of +5 diopters, meaning that the peripheral zone power value is +10 diopters. The width of the intermediate zone is at most equal to 1.5mm, for example 0.1mm to 1.5mm, depending on the manufacturing equipment. In another example, a myopic subject of-6 diopters, referred to as fast forward, may fit a coverage of 20% and a net power value of +8 diopters to +10 diopters. Thus, the peripheral zone has a power of +14 diopters to +16 diopters, and the intermediate zone has a width equal to 1.5mm at the maximum, for example, 0.1mm to 1.5 mm.

The quality of distance vision may also determine which local design may be used. For example, if a myopic subject fits a small distance zone and a high peripheral power value, complaining of distance vision blur, the next lens to try may be a medium distance zone with the same peripheral power value, or a small distance zone with a reduced peripheral power value. For example, a myopic subject of-3.5 diopters designed to fit 30% of the central zone and a net power of +5 diopters for the peripheral zone may be re-fitted with-3.5 diopters, 40% of the central zone and the same net value of +5 diopters, or a net power of-3.50 diopters, 30% of the central zone, and the peripheral zone of +3 diopters. In the first case, the peripheral zone power is +8.5 diopters, and in the second case +6.5 diopters.

The user of the method determines the value of the degree in the central region, the value of the degree in the peripheral region, and thus the value of the degree, based on the characteristics of the subject, thereby customizing the design of the medical device for the subject. Once the local design is selected and the degree values for the central region, the net degree and degree values for the peripheral region are determined, the design of the medical device is completed.

In one embodiment, the surface area of the pupil of the subject to be treated is measured. For example, the surface area of the pupil may be evaluated for the naked eye under photopic conditions and based on the pupil radius (S pi x r) when the subject gazes far away²) And (6) performing calculation. The surface area of the distance interval is represented by S₂Determined as (square root (%) X r). For example, the formula for a coverage of 30% is S-square root (0.3) x r, where r is the diameter of the pupil divided by 2.

In one embodiment, the surface area or diameter of the pupil may be determined using a database. For example, the database may include the average pupil diameter for a given population. The pupil diameter corresponding to the subject is obtained by determining to which population the subject to be treated belongs. The user must also measure the surface area of the subject's eye. An exemplary population may correspond to caucasian patients 6 to 9 years of age to whom the mean pupil diameter is associated. Another exemplary population may correspond to east asian patients 10 to 14 years of age.

Although in the above description each local design comprises a predefined percentage of the surface area of the pupil to be covered by the central and intermediate regions of the medical device, and the user is required to determine the degree values of the central and peripheral regions, those skilled in the art will appreciate that the local designs may each comprise a predefined net degree value. In this case, the user customizes the design of the medical device to the subject by selecting an appropriate local design according to the subject, i.e., selecting an appropriate predefined net power value according to the subject, and determining the percentage of the surface area of the pupil to be covered by the central and intermediate regions of the medical device according to the characteristics of the subject.

In one embodiment, the first partial design to be selected for a particular eye should be one that provides a minimal central region, taking into account the entire pupil surface area, without affecting vision at far distances. For myopic and hyperopic subjects, in the case of distance blur, the next local design to be selected should be the first available design with a larger central zone. If the refractive error develops, the next adapted local design is the first available design with a smaller central interval.

In the following, experimental results are given for the study of medical devices designed to manage the increase in axial length of the eye in the context of the development of ametropia. In particular, the results indicate that the medical device is effective for young myopes.

Purpose(s) to

The purpose of this study was to test the effectiveness of medical devices designed according to the above principles, and more particularly soft multifocal contact lenses, in controlling the progression of ametropia and elongation of the axial length of the eye in a group of young myopes.

Method of producing a composite material

This was a prospective randomized crossover study in which 22 patients aged 7 to 12 years who exhibited progressive myopia were studied. The study was conducted at the Clinique university visual clinical institute (Clinique Universal de la Vision) approved by the research Bureau of the ethics Committee. An intervention was used and compared to a control. Myopia progression and axial growth are estimated annually and compared between interventions and controls.

Patient selection

Patients were included in the study if they met the following criteria: (1) myopia is at least-1 diopter but not more than-4 diopter; (2) confirming that any meridian of any eye has developed at least-0.25 diopters over the last 6 months; (3) refractive astigmatism of less than-1 diopter; (4) the best corrected vision is 20/20 for each eye; (5) there were no myopia control strategies or devices in the last 6 months; (6) no binocular vision impairment; (7) good eye health; (8) no medication was taken that could affect vision or tear film stability; (9) no contact lens wear contraindications; (10) no allergy to any product used in this study; (11) understanding the purpose and schedule of clinical studies; (12) the patient's parents or legal guardians provide a list of informed consent signatures.

This study included 5 visits within 1 year: (1) baseline data acquisition and contact lens customization; (2) delivering the lens; (3)14 days of control examination; (4) checking for 180 days; (5) delivering a new lens; and (6)360 days of final control. During the first visit, a comprehensive eye examination was performed, including (1) medical history, with emphasis on risk factors for myopia development, past correction methods and modes of development (2) supplementary and non-supplementary vision assessment at distance and near (3) covering tests at distance and near by current optical correction (4) assessment of near eye deviation using phoropter (5) assessment of accommodative convergence/accommodation ratio using gradient method and phoropter (6) assessment of accommodation lag at near using retinoscope (7) pupil diameter measurement using electronic pupillometer at near distance (8) corneal tomography using point source pupil hole reflection (9) based on schiepgauge (10) higher order aberration assessment using Hartman-Schack type aberrometer (11) ocular axial length measurement using infrared biointerometer (12) progression using electronic autorefractometer The test is performed and the same measurements (e.g., 25 minutes after instillation) are repeated after 2 drops of 1% cyclopentolate eye drops are instilled in each eye (13) anterior segment assessment using a slit lamp and (14) intraocular pressure and corneal hysteresis measurements using an eye response analyzer.

Finally, one eye was randomly selected to wear the medical device (intervention), while the other eye was contrasted with a monofocal soft contact lens made of the same material. Both lenses are designed and customized according to the corneal topography and its parameters, cycloplegic diopters, and pupillary area.

More specifically, the medical device comprises a central zone having a power equal to the measured ciliary muscle diopter value, a transition zone surrounding the central zone and having a width of about 1.0mm and a peripheral zone having an add power of +5 diopters, wherein the surface area of each of the central and peripheral zones is selected for each patient according to the surface area of the pupil of the eye. The control lens was made of a single central zone of equal power to the cycloplegic diopter and 6mm wide. This area is surrounded by a peripheral area of no effective power. The overall diameter of the lens is selected based on the corneal diameter determined by tomographic evaluation. The central curve of the lens is selected according to the mean central curvature of the cornea. Thus, each pair of lenses is completely custom made for the patient.

At visit 2, the lens order is checked and delivered to the patient, with the contact lens in place, the test is performed of (1) assessing lens wear (position and movement) using slit lamps, if the lens is assessed as being inadequate, customizing another set of contact lenses based on the assessment results, if the lens is found to be correct, (2) performing distance and near acuity measurements using a C L andoll chart under photopic conditions, (2) performing a hypermetropic measurement at distance using an optometer (3) performing an eye deviation (phoria) assessment at distance and near using an optometer (4) performing a topography measurement on the lens using a tomography scanner (5) performing a high order aberration measurement using a Hartman-Schack type aberrometer (6) insertion and removal instructions provided to the patient and their parents (7) contact lens care recommendations and next appointment schedule.

At visit 3, a partial ophthalmic examination was conducted including (1) medical history related to the wearing of study lenses provided 14 days ago (2) evaluation of lenses on eye for distance and near visual acuity after lens wear (3) and evaluation of eye health after lens removal using slit lamps (4) patient recommendations and next appointment schedule.

At visit 4, a partial ophthalmic examination was performed, including (1) case history (2) distance and near vision measurements with lenses (3) telediometry (4) near eye deviation (strabismus), accommodative convergence/accommodation ratio using an optometer, evaluation of accommodative lag using a retinoscope (5) evaluation of pupil diameter using an electronic pupillometer (6) evaluation of distance subjective refraction using an optometry instrument without contact lens (7) evaluation of anterior segment of the eye using a slit lamp (8) measurement of axial length of the eye using an infrared bioassay (9) corneal tomography using a Scheimpflug type tomography scanner (10) instillation of 2 drops of 1% cyclopentolate followed by autorefraction using an electronic autorefractor (e.g. 25 minutes after instillation) (11) fundus examination using a magnifying glass and a slit lamp at mydriasis. Designing and customizing new lenses complies with a crossover protocol. This means that the eye wearing the medical device first now wears the monofocal lens, whereas the eye wearing the monofocal lens first now wears the medical device. As previously described, both lenses are customized for each eye of the patient.

At visit 5, new lenses were delivered and a partial ophthalmic examination was performed, including (1) brief medical history (2) distance and near visual acuity after contact lens wear (3) slit lamp assessment of lens and anterior segment of the eye (4) patient recommendations and review of care regimens. Next appointment schedules are also discussed.

At visit 6, a partial eye examination was performed, including the same test procedures as were performed at the initial visit.

Three patients did not appear at the last visit and three other patients were excluded because they did not follow the lens wearing schedule during the study. A total of 16 patients were obtained as a complete data set.

Results

On average, at 6 months, the eyes wearing the medical devices developed-0.16 +0.24 diopters (expected to be-0.32 diopters per year) and the axial length increased by +0.14+0.10mm, while the control-equipped eyes developed-0.32 +0.33 diopters (0.64 diopters per year) and increased by +0.15+0.13mm, respectively. When comparing medical devices to controls, there is a significant difference in myopia progression, representing an effective rate of 50% at 6 months and 61% at one year. Regarding the ocular axial length, there was a significant difference for the eyes wearing the control first and then the medical device for the last 6 months (control +0.16mm, medical device 0.10 mm). The same effect was not observed for eyes wearing medical devices first (+0.13mm) and then the control (+0.17 mm).

Conclusion

The designed medical device is effective in controlling myopia progression and also effective in controlling axial length growth when the eye is first wearing a control lens.

The embodiments of the invention described above are intended to be exemplary only. Accordingly, the scope of the invention is intended to be limited only by the scope of the appended claims.

Claims

1. A medical device for managing axial length growth of an eye of a subject, the eye having a pupil, the device comprising:

a central region having a first degree;

a transition zone surrounding the central zone and having a width equal to 1.5mm at the most; and

a peripheral region surrounding the transition region, the peripheral region having a second degree,

wherein a surface area of each of the central region and the peripheral region is selected as a function of a surface area of a pupil of the eye.

2. The medical device of claim 1, wherein the surface area of the pupil of the eye corresponds to the surface area of the pupil of the eye evaluated under photopic conditions when the subject is gazing with the naked eye at distance.

3. The medical device of claim 1 or 2, wherein the central region and the peripheral region are adapted to treat at least one of myopia and astigmatism.

4. The medical device of claim 3, wherein the surface area of the central region and the transition region is about 20% to about 40% of the surface area of the pupil of the eye.

5. The medical device of claim 4, wherein for the near vision, the first power of the central zone is about-0.25 diopters to about-30 diopters; and for the astigmatism, the first power of the central zone is about-0.25 diopters to about-10 diopters.

6. The medical device of claim 5, wherein the second degree of the peripheral region is determined from a target net degree and the first degree of the central region.

7. The medical device of claim 6, wherein the target net power is about +3.5 diopters to about +10 diopters and the second power is about +3.75 diopters to about +20 diopters.

8. The medical device of claim 6, wherein the target net power is equal to about +5 diopters.

9. The medical device of claim 1 or 2, wherein the central region and the peripheral region are adapted to treat hyperopia.

10. The medical device of claim 9, wherein the surface area of the central region and the transition region is about 30% to about 50% of the surface area of the pupil of the eye.

11. The medical device of claim 10, wherein the first power of the central region is about +0.25 diopters to +25 diopters.

12. The medical device of claim 11, wherein the second degree of the peripheral region is determined from a target net degree and the first degree of the central region.

13. The medical device of claim 12, wherein the target net power is about-3.5 diopters to about-10 diopters and the second power of the peripheral region is about-3.75 diopters to-20 diopters.

14. The medical device of claim 13, wherein the peripheral region has a target net power equal to about-5 diopters.

15. The medical device of claim 1 or 2, wherein the central region and the peripheral region are adapted for treatment of presbyopia.

16. The medical device of claim 15, wherein the medical device corresponds to a remote central device.

17. The medical device of claim 16, wherein the surface area of the central region and the transition region is about 20% to about 30% of the surface area of the pupil of the eye.

18. The medical device of claim 17, wherein the first power of the central region is about-30 diopters to about +25 diopters.

19. The medical device of claim 18, wherein the peripheral region is provided with an add power of about +0.25 diopters to about +5 diopters.

20. The medical device of claim 19, wherein the add power of the peripheral region is equal to about +2.5 diopters.

21. The medical device of claim 15, wherein the medical device corresponds to a near-central device.

22. The medical device of claim 21, wherein the surface area of the central region and the transition region is about 10% to about 30% of the surface area of the pupil of the eye.

23. The medical device of claim 22, wherein the second power of the peripheral region is about-30 diopters to +25 diopters.

24. The medical device of claim 23, wherein the central zone is provided with an add power of about +0.25 diopters to about +5 diopters.

25. The medical device of claim 24, wherein the add power of the central zone is equal to about +2.5 diopters.

26. The medical device of any one of claims 1 to 25, wherein the second degree is constant throughout the peripheral region.

27. The medical device of any one of claims 1-25, wherein the peripheral region includes a plurality of angular portions, each angular portion having a respective degree.

28. The medical device of claim 27, wherein two adjacent ones of the plurality of angular portions are provided with different degrees.

29. The medical device of claim 28, wherein the respective degrees are equal to one of a first degree of the central region and a second degree of the peripheral region.

30. The medical device of any one of claims 1-25, further comprising an outer region surrounding the peripheral region.

31. The medical device of claim 30, further comprising a transition region between the peripheral region and the outer region, the transition region having a width up to about 1.5 mm.

32. The medical device of claim 30 or 31, wherein the outer region comprises a plurality of angular portions, each angular portion having a respective degree.

33. The medical device of claim 32, wherein two adjacent ones of the plurality of angular portions are provided with different degrees.

34. The medical device of claim 33, wherein the respective degrees are equal to one of a first degree of the central region and a second degree of the peripheral region.

35. The medical device of any one of claims 33-34, wherein the outer region is divided into an even number of the angular portions.

36. The medical device of any one of claims 1 to 29, wherein the medical device is a corrective lens.

37. The medical device of claim 36, wherein the corrective lens is a contact lens.

38. The medical device of claim 37, wherein the contact lens is a soft contact lens.

39. The medical device of claim 37, wherein the contact lens is one of a rigid lens, a gas permeable lens, and a hybrid lens.

40. The medical device of claim 36, wherein the corrective optic is an intraocular optic.

41. A medical device for managing axial length growth of an eye of a myopic subject, the eye having a pupil, the device comprising:

a central region having a first power for adjusting distance vision;

wherein the surface area of the central zone and the transition zone is about 20% to about 40% of the surface area of the pupil of the eye, and wherein the first power of the central zone is about-0.25 diopters to about-30 diopters.

42. The medical device of claim 41, wherein the surface area of the pupil of the eye corresponds to the surface area of the pupil of the eye evaluated under photopic conditions when the subject is gazing with the naked eye at distance.

43. The medical device of claim 41 or 42, wherein the second degree of the peripheral region is determined from a target net degree and the first degree of the central region.

44. The medical device of claim 43, wherein the target net power is about +3.5 diopters to about +10 diopters and the second power is about +3.75 diopters to about +20 diopters.

45. The medical device of claim 44, wherein the target net power is equal to about +5 diopters.

46. The medical device of any one of claims 41-45, wherein the second degree is constant throughout the peripheral region.

47. The medical device of any one of claims 41-45, wherein the peripheral region includes a plurality of angular portions, each angular portion having a respective degree.

48. The medical device of claim 47, wherein two adjacent ones of the plurality of angular portions are provided with different degrees.

49. The medical device of claim 48, wherein the respective degrees are equal to one of a first degree of the central region and a second degree of the peripheral region.

50. The medical device of any one of claims 41-45, further comprising an outer region surrounding the peripheral region.

51. The medical device of claim 50, further comprising a transition region between the peripheral region and the outer region, the transition region having a width up to about 1.5 mm.

52. The medical device of claim 50 or 51, wherein the outer region comprises a plurality of angular portions, each angular portion having a respective degree.

53. The medical device of claim 52, wherein two adjacent ones of the plurality of angular portions are provided with different degrees.

54. The medical device of claim 53, wherein the respective degrees are equal to one of a first degree of the central region and a second degree of the peripheral region.

55. The medical device of any one of claims 52-54, wherein the outer region is divided into an even number of the angular portions.

56. The medical device of any one of claims 41 to 55, wherein the medical device is a corrective lens.

57. The medical device of claim 56, wherein the corrective lens is a contact lens.

58. The medical device of claim 57, wherein the contact lens is a soft contact lens.

59. The medical device of claim 57, wherein the contact lens is one of a rigid lens, a gas permeable lens, and a hybrid lens.

60. The medical device of claim 56, wherein the corrective lens is an intraocular lens.

61. A method for managing axial length growth of an eye of a subject, comprising:

creating a central region within a cornea of an eye of the subject, the central region having a first degree;

creating an intermediate zone within the cornea of the eye surrounding the central zone, the intermediate zone having a width equal to about 1.5mm at the most; and

creating a peripheral region within a cornea of the eye surrounding the intermediate region, the peripheral region having a second degree,

62. The method of claim 61, wherein the creating the central, intermediate and peripheral regions comprises propagating a laser beam on a cornea of the eye.

63. The method of claim 61 or 62, wherein the central region and the peripheral region are adapted to treat at least one of myopia and astigmatism.

64. The method of claim 63, wherein the surface area of the central region and the transition region is about 20% to about 40% of the surface area of the pupil of the eye.

65. The method of claim 64, wherein for the near vision, the first power of the central zone is about-0.25 diopters to about-30 diopters; for the astigmatism, the first power of the central zone is about-0.258 diopters to about-10 diopters.

66. The method of claim 65, wherein the second degree of the peripheral region is determined from a target net degree and the first degree of the central region.

67. The method of claim 66, wherein the target net power is about +3.5 diopters to about +10 diopters and the second power is about +3.75 diopters to about +20 diopters.

68. The method of claim 67, wherein the target net power is equal to about +5 diopters.

69. The method of claim 61 or 62, wherein the central region and the peripheral region are adapted to treat hyperopia.

70. The method of claim 69, wherein the surface area of the central region and the transition region is about 30% to about 50% of the surface area of the pupil of the eye.

71. The method of claim 70, wherein the first power of the central region is about +0.25 diopters to +25 diopters.

72. The method of claim 71, wherein the second degree of the peripheral region is determined from a target net degree and the first degree of the central region.

73. The method of claim 72, wherein the target net power is about-3.5 diopters to about-10 diopters and the second power of the peripheral region is about-3.75 diopters to-20 diopters.

74. The method of claim 73, wherein the target net power of the peripheral region is equal to about-5 diopters.

75. The method of claim 61 or 62, wherein the central region and the peripheral region are adapted for treatment of presbyopia.

76. The method of claim 75, wherein the surface area of the central region and the transition region is about 20% to about 30% of the surface area of the pupil of the eye.

77. The method of claim 76, wherein the first power of the central region is about-30 diopters to about +25 diopters.

78. The method of claim 77, wherein the peripheral region is provided with an add power of about +0.25 diopters to about +5 diopters.

79. The method of claim 78, wherein the add power of the peripheral region is equal to about +2.5 diopters.

80. The method of claim 75, wherein the surface area of the central region and the transition region is about 10% to about 30% of the surface area of the pupil of the eye.

81. The method of claim 80, wherein the second power of the peripheral region is about-30 diopters to +25 diopters.

82. The method of claim 81, wherein the central zone is provided with an add power of about +0.25 diopters to about +5 diopters.

83. The method of claim 82, wherein the add power of the central zone is equal to about +2.5 diopters.

84. The method of any one of claims 61-83, wherein the second degree is constant throughout the peripheral region.

85. The method of any of claims 61-83, wherein the creating the peripheral region comprises creating a plurality of angular portions within the peripheral region, each angular portion of the plurality of angular portions having a respective degree.

86. The method of claim 85, wherein two adjacent ones of said plurality of corner portions are provided with different degrees.

87. The method of claim 86, wherein the respective degrees are equal to one of a first degree of the central region and a second degree of the peripheral region.

88. The method of any one of claims 61-83, further comprising: an outer region is created around the peripheral region.

89. The method of claim 88, further comprising: creating a transition region between the peripheral region and the outer region, the transition region having a width equal to about 1.5mm at the most.

90. The method of claim 88 or 89, wherein the outer region comprises a plurality of angular portions, each angular portion having a respective degree.

91. The method of claim 90, wherein two adjacent ones of the plurality of corner portions are provided with different degrees.

92. The method of claim 91, wherein the respective degrees are equal to one of a first degree of the central region and a second degree of the peripheral region.

93. The method of any one of claims 90 to 92, wherein the outer region is divided into an even number of said angular portions.

94. A method for treating an eye condition in a subject, the method comprising:

determining a refractive error of the eye of the subject;

determining a surface area of a pupil of the eye; and

providing a medical device according to any one of claims 1 to 40.

95. A method for treating myopia of an eye of a subject, the method comprising:

determining that the eye of the subject is affected by myopia;

determining a surface area of a pupil of the eye; and

providing a medical device according to any one of claims 41 to 60.