JPS6340293B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to soft contact lenses and intraocular lenses and methods of making such lenses. The lens is made from a polymer core and coated with a plasma polymerized ultra-thin barrier. The core is silicone or polyurethane or polymethyl methacrylate. Gaseous monomers used in plasma polymerization are, for example, hydrocarbons, halogenated hydrocarbons and mixtures thereof. Recently, there has been increased interest in the development of permanently worn corneal contact lenses, as there are several situations in which such lenses are highly needed. Elderly patients, especially those who have undergone cataract surgery, cannot wear and remove any type of contact lenses every day, and these patients are forced to wear glasses instead of contact lenses. At that time, I lost a lot of my vision.
This problem is even more important for younger children who have had cataract removal in one eye due to injury or congenital causes. In these cases, incorrect contact lens fitting can lead to permanent vision loss (amblyopia). In these cases, the daily insertion and removal of lenses is left to the caregiver, something that is almost impossible for some children. dry eye, alkaline corneal burns,
Permanent contact lenses are also used in many treatment settings such as recurrent corneal abrasions, herpetiform corneal ulcers, and corneal edema. Additionally, lenses that can be permanently worn would also be acceptable to patients who wish to wear and remove lenses daily. Conventional hard contact lenses made of polymethyl methacrylate, which is not oxygen permeable, cannot be worn for more than 12 to 24 hours and have never been proposed as permanently worn lenses. However, soft contact lenses are now being used for permanent wear. There are basically two types,
One type uses a material such as silicone, which derives its softness from the inherent properties of that material.
The other type uses materials such as polymers of hydroxyethyl methacrylate (HEMA) and copolymers of HEMA with other hydrophilic monomers, the softness of which is obtained through hydration of the polymer. It will be done.
An example of this type is the Bausch &
Lomb soft lenses and Griffin Natural lenses. Each of these types has advantages and disadvantages, and no lens is ideal. Silicone rubber is, in theory, an ideal polymer as a raw material for the production of permanent soft contact lenses for two reasons. First, silicones are naturally soft and have good optical clarity. Second, silicone has the highest gas permeability of many polymers known today, with most polymers having gas permeability two orders of magnitude lower than silicone rubber. However, silicone has significant drawbacks that prevent it from being used successfully as a contact lens. Silicone is highly permeable to substances in the tear film, including lipids, lipid-soluble substances, proteins, oxygen, and other large molecule substances in the tear film. When a silicone contact lens is placed on the cornea, lipids and other substances from the tear film adhere to and enter the lens. The lenses rapidly lose their optical clarity and the wearer's eyes become irritated and red. For this reason, it is necessary to stop wearing the lens. Lipids and other substances seep into contact lenses, so they cannot simply be scraped off and the entire lens must be replaced. Silicone is also hydrophobic, so it doesn't wet well.
This makes it uncomfortable to wear. The tear film on the human cornea is a watery fluid, but it is not just water or warm water;
Contains lipids, proteins, enzymes and other macromolecular substances. For example, making a silicone surface hydrophilic does not necessarily prevent lipids and other substances in the tear film from reducing the optical clarity of the silicone. Soft contact lenses currently on the market are made of hydrophilic polymers such as hydroxyethyl methacrylate (HEMA) hydrogels and copolymers of HEMA and other hydrophilic monomers. The advantage of such soft contact lenses is that they are comfortable to wear because the material is flexible. Other claimed advantages, such as having a high oxygen permeability and a wettable hydrophilic surface, are incorrect. The high permeability of hydrogels to relatively large permeable substances has often led to the erroneous notion that hydrogels are suitable for contact lenses due to their high oxygen permeability and the ability of oxygen to easily permeate through lens materials. lead The high permeability to relatively large permeable substances is a result of the high level of water content in the material, which increases the mobility of the polymer molecules. Because oxygen has a relatively small molecular size, the movement of oxygen molecules through the polymer does not require such high mobility.
Therefore, the increase in mobility due to the presence of water (solvent) does not affect oxygen permeability in the same way as larger permeable materials. The solubility of oxygen in water is much smaller than the solubility of oxygen in many polymers. In hydrogels, a significant portion of the material is occupied by water molecules with low oxygen solubility. Therefore, the net effect of high water content in the hydrogel is rather reduced oxygen permeability compared to the dry polymer. It is important to note that many manufacturers claim that oxygen permeability increases with increasing water content of soft contact lenses. Many manufacturers also claim that as the water content increases, permanent wear lenses will be easier to manufacture. However, the actual effect is quite the opposite since oxygen permeability decreases as water content increases. It is also claimed that HEMA type soft contact lenses are wettable and hydrophilic. Although contact lens surface wettability is clearly an important advantage of hydrogel contact lenses, many hydrogel contact lenses do not have as high a wettability as would be expected from their high water content.
Hydrophilic polymer molecules such as HEMA consist of a hydrophobic backbone and hydrophilic substituent (pendant) moieties.
Because of this hydrophilic side group, HEMA monopolymer hydrogels contain 45-50% water by volume. However, one must be careful in determining the wettability of such hydrogel contact lens surfaces.
The contact lens surface is the interface between air and hydrogel (which contains a large amount of water). At this interface,
The hydrophilic side groups of the hydrogel clearly prefer to face the water-containing phase, while the hydrophobic part of the molecule becomes facing the air phase. Because of this phenomenon, the hydrogel contact lens surface is hydrophobic and
It is considered not to be hydrophilic. Of the three main features claimed as advantageous features of hydrogel contact lenses, namely softness, surface wettability and high oxygen permeability, softness is the only advantage that most wet/soft contact lenses have. It can be obtained with Wet and soft contact lenses also have many disadvantages.
In order to solve the disadvantages of wet/soft contact lenses, the following must be considered. 1 Keeping wet and soft contact lenses sterile is much more difficult than keeping dry contact lenses. 2. The equilibrium water content of hydrogel lenses depends on the nature of the surrounding medium. 3. The optical power of wet/soft contact lenses also changes depending on the state of the surrounding medium, and as a result, it is difficult to manufacture lenses with the exact optical performance required for the original state. Have difficulty. 4. Wet soft contact lenses tend to adhere to the corneal surface due to aspiration, preventing normal and free exchange of lachrymal fluid and reducing oxygen supply to the cornea. 5 Due to the highly swollen state of hydrogels, their permeability to relatively large molecules present in tear fluid is quite high. Therefore, certain lipids and lipid-soluble substances as well as water-soluble substances can penetrate into the hydrogel network and become wet.
Altering the balance between the hydrophilic and hydrophobic phases of soft contact lenses. In view of these problems, many attempts have been made to convert the hydrophobic surfaces of silicone contact lenses to hydrophilic surfaces. A coating method of this type practiced by Dow-Corning is the use of titanate solutions. This is a dipping solution and is used as a temporary coating. This method has not been successful and is currently obsolete. U.S. Pat. No. 4,143,949 describes the application of an ultra-thin coating of a hydrophilic polymer under the action of a plasma glow discharge to integrally bond the coating to the surface of a hydrophobic lens. A method of improving the hydrophobic surface of a hard or soft contact lens by making the lens hydrophilic is disclosed. The purpose of such hydrophilic treatment is to impart wettability to the lens. Since each of the monomers mentioned in this patent contains oxygen, the crosslinked polymer forming the coating is not as intimate. This allows lipids and other large molecules to enter the lens, making it optically opaque, for example if the lens is made of silicone. “Ultrathin Coating by Plasma applied to corneal contact lenses” by Yasuda et al.
Polymerization Applied to Corneal Contact
A paper entitled “Lens)” [J.Biomed.Mater.Res.,
9, 629-643 (1975)] discloses a method for coating hard contact lenses by glow discharge polymerization in the presence of acetylene, nitrogen and water. This method uses glow discharge polymerization to transform the hydrophobic surface of a contact lens into a hydrophilic surface. This surface modification improves the water wettability of the contact lens and also reduces mucus accumulation on the surface between the lens and the cornea. However, because the atmosphere of glow discharge polymerization contains nitrogen and oxygen derived from water, the crosslinking of the resulting polymer is not very tight, and such coatings cannot be used, for example, in silicone soft lenses. In some cases, this may allow the infiltration of lipids. US Pat. No. 3,389,012 discloses a method of coating only the periphery of a hard lens with a tetrafluoroethylene polymer to increase wearer comfort. US Pat. No. 3,925,178 discloses the use of a plasma containing excited water molecules for surface treatment of contact lenses. This treatment method is temporary, as the authors themselves admit in this patent. The lens surface gradually returns to hydrophobicity. Moreover, this method does not provide a barrier to prevent lipid and protein diffusion into the lens interior. US Pat. No. 3,599,105 describes the use of plasma containing oxygen or water vapor to treat contact lens surfaces. This treatment is also temporary, and the lens surface gradually returns to hydrophobicity. Moreover, this method does not provide a barrier to prevent lipid and protein diffusion. Thus, there remains a need for permanently worn corneal contact lenses which are lacking in the prior art. Hard lenses made of polymethacrylate have low oxygen permeability, are uncomfortable, and have a limited amount of time in the eye.
Hydrogel soft lenses have a number of drawbacks, and silicone soft lenses are lipid permeable and their optical clarity deteriorates rapidly. Additionally, the use of intraocular lenses for the correction of aphakia is currently one of the most active and rapidly growing fields of all medicine. The traditional use of spectacle lenses for this purpose has too many drawbacks. The use of contact lenses, especially soft contact lenses, overcomes many of the disadvantages of heavy and vision-restricting eyeglasses. However, these contact lenses also have certain drawbacks and often require strong motivation for the user. Intraocular lenses offer much greater theoretical and practical possibilities for both optical correction of aphakia and restoration of binocular vision. About 30 years ago, the first clinically acceptable transplant procedure was performed by Harold Ridley in London.
Ridley). Although the initial results reported by Ridley and others were not very impressive, they were encouraging enough to stimulate further efforts. past 25
Over the years, significant improvements in visual outcomes have been obtained and complications encountered with intraocular surgery have decreased. These advances are due to improvements in surgical techniques, changes in lens design, advances in training facilities, and advances in instrument design and materials. Currently, approximately 500,000 cataract surgeries are performed annually in the United States, and more than 50,000 intraocular lenses are implanted into patients' eyes. There are the following four complications currently caused by intraocular lenses, and these complications can be alleviated by the present invention. [1] It was observed that there was more inflammation after cataract surgery with intraocular lens implantation than after cataract surgery alone.
Two types of inflammation were seen: acute and chronic. In acute cases, the reaction may be so severe that it appears to be an acute infection. The present inventors have observed four cases of acute inflammation in their clinical practice, and data from one such lens manufacturer states that for a given batch of lenses, 1 in 40 patients
The occurrence of acute inflammation (sterile anterior chamber empyema) in humans has been reported. Similar manifestations have been reported by other manufacturers of such lenses. The acute inflammatory reaction after intraocular lens insertion shows copious fibrous exudate and cellular infiltration in the anterior chamber and vitreous. Since no microorganisms have been cultured from the tears of these eyes, this reaction is known as aseptic uveitis. In many cases, vision is permanently lost as a result of this reaction. Usually, if an intraocular lens is not inserted after cataract surgery, no chronic inflammation occurs. It is known that mild inflammation persists for months or years after intraocular lens insertion. It is thought that retinal swelling (cystoid macular edema) occurs after chronic inflammation. Although this can occur after cataract surgery without intraocular lens insertion, it occurs more commonly after intraocular lens insertion. To suppress this inflammation, many patients are given long-term anti-inflammatory drugs (steroids).
This makes the eyes more susceptible to infections. American Academy of Ophthalmology
In a recent conference (1978), Galin ¹ demonstrated that chronic inflammation persists for 1 year after intraocular lens insertion, but that inflammation does not persist if intraocular lens insertion is not performed after cataract surgery. It was clearly shown. Monomers from polymethyl methacrylate or other chemicals such as benzoyl peroxide used in the manufacture of plastics are said to leak into the eye, causing acute and chronic inflammation. It is well known that methyl methacrylate vapors are toxic to manufacturing personnel and must be managed very carefully2,3. It is not possible to produce polymethyl methacrylate without free monomers. [2] It is known that ultraviolet light can depolymerize polymethyl methacrylate to produce free monomers. When this occurs after implantation of the lens into the eye, free monomer is released into the eye. Thus, intraocular lenses can cause constant intraocular irritation. It is known that ultraviolet radiation damages the retina.
Normally, the human lens absorbs all incident ultraviolet light, preventing it from reaching the retina. Polymethyl methacrylate absorbs only a portion of the UV radiation, so some of it reaches the retina (Mainster ⁸ ). [3] Another important problem in the use of intraocular lenses is the loss or damage of corneal endothelial cells due to contact with the surface of the intraocular lens. “Boume and Kaufman
Recent studies by Kaufman ⁵ and Forstat et al. showed that, on average, approximately half of the central corneal endothelial cells are lost after intraocular lens (IOL) insertion.'' ⁶ To prevent this, polyvinylpyrrolidone and methylcellulose were first proposed as coatings.These are viscous substances that were coated by dipping the lens in polyvinylpyrrolidone or methylcellulose before being inserted into the eye.These coatings Although it reduced cell loss, it made lens insertion difficult and interfered with proper visualization of the lens.
These substances are not currently used clinically. Other researchers [Kirk et ^al.7 ] have used less viscous fluids such as normal saline, Plasma TC199, albumin, and serum to prevent cell loss. Each intraocular lens was dipped into one of these substances and then inserted into the eye. All substances reduced cell loss to some extent, with serum being the best;
None of these methods are currently in use. This is due to the antigenicity and lack of sterility of substances such as albumin and serum. It should be emphasized that all these coatings are temporary, wash out in the eye, and are only intended to reduce the complication of endothelial cell damage. . [4] Another thing patients experience with intraocular lenses
One problem is glare. This occurs because light is reflected from the lens surface. This causes discomfort and reduces vision. This fact is well known in the field of camera lenses that are coated to reduce glare and improve image contrast. Currently, intraocular lenses are not coated because the coatings can be toxic. Accordingly, a primary object of the present invention is to provide a permanently worn corneal contact lens. Another object of the present invention is to provide a corneal contact lens that is soft to provide comfort to the wearer. Another object of the invention is to provide a corneal contact lens that is lipid and polymer impermeable to provide long-term optical clarity. Another object of the invention is to provide a corneal contact lens that is highly oxygen permeable and has long-term wettability. These purposes basically contain neither nitrogen nor oxygen and contain (a) hydrocarbons, (b) halogenated hydrocarbons, (c) halogenated hydrocarbons and hydrogen, (d) hydrocarbons and elements. halogen, and (e) a reaction product obtained from a plasma polymerization process carried out in a gaseous atmosphere, consisting essentially of at least one compound selected from the group consisting of halogens, and (e) mixtures thereof. By providing a soft corneal contact lens consisting of a soft, highly oxygen permeable polymeric lens having a transparent, lipid impermeable and highly oxygen permeable barrier coating formed thereon. achieved. These objectives are essentially: (a) preparing a soft, highly oxygen-permeable polymeric lens; (b) placing the lens in a plasma polymerization apparatus; and (c) (1) ) hydrocarbon, (2) halogenated hydrocarbon, (3) halogenated hydrocarbon and hydrogen, (4) hydrocarbon and elemental halogen, and (5) at least one compound selected from the group consisting of a mixture thereof. (d) providing a gas atmosphere in the device consisting essentially of (but containing neither nitrogen nor oxygen); and (d) combining the compound with the lens under conditions sufficient for the compound to generate a plasma. producing a soft corneal contact lens by forming an ultra-thin, lipid-impermeable, highly oxygen permeable, optically clear barrier coating on the lens surface, which is a polymerization reaction product coating; It is also achieved by The resulting lens is thus coated with a tightly cross-linked ultra-thin barrier that prevents the infiltration of lipids and other macromolecules such as proteins, enzymes and other substances present in the tear film. protection and provides long-lasting optical clarity. The resulting lenses are highly oxygen permeable and have long-lasting wettability, allowing for long-term wear. Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the accompanying drawings, discloses preferred embodiments of the invention. Another object of the invention is to provide a method for encapsulating intraocular lenses to solve all the problems listed above. such as plasma polymers of the materials described in the section on contact lenses,
An inert, biologically acceptable material can be used to form an ultra-thin film around an intraocular lens. These materials form a barrier to the passage of small molecules and prevent the diffusion of free monomers and other trace materials from the intraocular lens.
Because of these substances, acute or chronic inflammation is prevented. Another object of the invention is to add it to the intraocular lens before encapsulating the lens. It is an object of the present invention to provide a lens structure having a colored substance for reducing glare or absorbing ultraviolet rays. Thus, the diffusion of free monomers released by UV radiation should also be prevented. Yet another object of the present invention is to provide an encapsulated lens that can reduce endothelial cell loss due to contact between endothelial cells and the lens surface. Our studies have shown that encapsulation with materials such as plasma polymers of methane, surface oxidized by Ar/O ₂ plasma, prevents such endothelial cell loss. Below, a method for covering soft contact lenses will be explained. This method of coating applies equally to intraocular lenses. The only difference is that the core material is polymethyl methacrylate instead of silicone or other soft polymer. The present invention essentially consists of a soft polymeric lens with a hydrophilic, tightly crosslinked polymeric barrier coating. This provides lipid and polymer impermeability and long-lasting wettability, allowing permanent attachment. The polymeric lens may be made of silicone polymers, silicone copolymers, polyurethanes or soft, optically clear, highly oxygen permeable polymeric materials suitable for use in corneal contact lenses. . Silicone polymers, copolymers or interpolymers are preferred. The barrier coating is applied at a very thin thickness so that the optical clarity of the final structure is maintained and the lens is comfortable for the wearer. The thickness is approx.
100 to about 2000 Å. The application of barrier coatings is by plasma polymerization methods, which are described in more detail below. During this polymerization process, the polymeric lens is exposed to a gaseous atmosphere (but without nitrogen or oxygen) that forms a tightly crosslinked barrier through polymerization. This gas atmosphere consists essentially of (a) hydrocarbons, (b) halogenated hydrocarbons, (c) halogenated hydrocarbons and hydrogen, (d) hydrocarbons and elemental halogens, and (e) mixtures thereof; It consists of at least one compound selected from the group consisting of. Any hydrocarbon that can be polymerized in a plasma polymerization apparatus can be used. However, since hydrocarbons must be in a gaseous state during polymerization, their boiling point is approximately 200% at 1 atm.
Must be below ℃. It is also believed that the tightness or porosity of barrier coatings formed by hydrocarbons is a function of the number of carbons present in the monomer. Thus, hydrocarbons with a low number of carbon atoms are preferred. It is also preferred that the hydrocarbon be fully saturated, ie, free of double or triple carbon-carbon bonds, as unsaturation has been shown to lead to a somewhat rough barrier structure. Hydrocarbons suitable for use in the present invention consist of hydrocarbons having 6 or fewer carbon atoms.
Thus, methane, ethane, propane, butane,
Pentane, hexane, ethylene, propylene, butylene, cyclohexane, cyclohexene, benzene, pentene and acetylene constitute a group of hydrocarbons suitable for use in the present invention. A more preferred group of hydrocarbons for use in the present invention consists of saturated hydrocarbons of 6 or fewer carbon atoms, namely methane, ethane, propane, butane, pentane and hexane. An even more preferred group of hydrocarbons for use in the present invention consists of hydrocarbons that are saturated and have up to 3 carbon atoms, namely methane, ethane and propane. It is believed that the most preferred hydrocarbon for use in the present invention is methane. As previously mentioned, halogenated hydrocarbons can also be polymerized according to the present invention by plasma polymerization to form a barrier coating on the surface of a soft polymeric lens. Any halogenated hydrocarbon (eg, chlorotrifluoroethylene) can be used, including mixed halogenated hydrocarbons, that can be polymerized in a plasma polymerization apparatus. The boiling point of the halogenated hydrocarbon must be below about 200°C. Thus, fully or partially fluorinated hydrocarbons, fully or partially chlorinated hydrocarbons, fully or partially brominated hydrocarbons and fully or partially iodinated hydrocarbons can be used in the present invention. As with unsubstituted hydrocarbons, low boiling halogenated hydrocarbons are preferred. Similarly, halogenated hydrocarbons are also preferably saturated. Preference is given to fully fluorinated hydrocarbons, such as tetrafluoromethane, hexafluoroethane, tetrafluoroethylene, octafluoropropane, and the like. If it is desired to utilize a halogenated hydrocarbon to carry out the plasma polymerization process of the present invention,
To accelerate the polymerization apparatus, hydrogen gas is added to the halogenated hydrocarbon in an amount ranging from about 0.1 to about 5.0 volumes of hydrogen per volume of halogenated hydrocarbon, preferably for each halogen atom in the halogenated hydrocarbon molecule. It can be added in an amount consisting of 1/2 molar equivalent of hydrogen gas, for example, 1/2 mol of hydrogen per 1 mol of fluoromethane, 1 mol of hydrogen per 1 mol of difluoromethane, etc. The atmosphere may consist essentially of hydrogen and elemental halogen. Thus, elemental fluorine, chloromethane, acetylene, ethane, ethylene, propane, propylene, butane, butene, butadiene, etc. Preferred halogen gases are fluorine and chlorine, and preferred hydrocarbons consist of low molecular weight saturated hydrocarbons. Mixtures of any of the above compounds can also be used in the present invention. Thus, hydrocarbons, halogenated hydrocarbons and hydrogen can be used together. Hydrocarbons, elemental halogens and hydrogen can be used together. Such combinations will be readily apparent to those skilled in the art, and it will be understood that the scope of the claims of the present invention encompasses such combinations. Similarly, it is possible to add small amounts of accelerators as well as other substances to the atmosphere that do not significantly alter the final structure of the barrier coating, and the claims of the present invention cover such combinations. It can also be understood that it is inclusive. In this regard, it is important that there is no nitrogen or oxygen in any form, free or combined, in the atmosphere. This is because they result in rough crosslinks that favor lipid infiltration. It is important that the resulting lens has a highly hydrophilic surface to provide long-lasting wettability. In this regard, many of the compounds chosen to form the plasma gas atmosphere impart a highly hydrophilic surface to the resulting lens. If desired, an additional step of exposing the lens to oxygen or a mixture of oxygen and argon during the discharge can be performed. This step increases hydrophilicity. In some cases, this additional step can be omitted even if the coating is not initially hydrophilic. In some cases, it has been found that by simply exposing the lens to an ambient atmosphere, oxygen in the ambient atmosphere combines with free radicals on the lens surface, increasing the hydrophilicity of the surface. In the method of manufacturing a lens of the present invention, a soft polymer lens, ie, a core, is molded into the shape of a contact lens with predetermined dimensions by methods known in the art. This core is then placed into a plasma polymerization reactor. The compound to be used as gas atmosphere is placed in a reservoir with an inlet to the reaction chamber of the apparatus. A vacuum of less than about 1 millitorr is applied to the reaction chamber. The reaction chamber containing the hydrophobic lens and preferably 10 to 50 millitorr of the compound in vapor state is subjected to electromagnetic radiation to initiate an electrical discharge, ionizing the vaporized compound and discharging it onto the surface of the hydrophobic lens. The ionized substance is polymerized integrally with the surface. During each discharge, the gas inlet from the reservoir is held in an open position to provide a constant flow rate of gaseous compound into the reaction chamber as it is consumed. The frequency of the electromagnetic radiation used can vary over a wide range and depends primarily on the equipment used. The power used depends on factors such as the surface area of the electrode and the flow rate and pressure of the monomer used. Four different structures can be used to support the lens for discharge operations. The first structure shown in FIGS. 1 and 2 consists of a pair of opposing parallel support rods 1 and 2 interconnected at their ends by rods 3 to form a frame. Between the rods 1 and 2 there are a plurality of annular rings 4, each ring supported by a pair of arms 5 and 6;
are respectively fixed to one of the rods and to one of the diametrically opposite points of the annular ring. Second
As can be seen, each ring 4 has an arcuate slot on its inner surface. The periphery of each core 8 fits within this arcuate slot, thereby supporting each core for exposure to plasma polymerization. The periphery of each core fits into the slot,
Therefore, since it is not coated while being supported in this manner, a second coating step is used, in which the core is supported so that the core periphery is exposed. This is accomplished by using the support device shown in FIGS. 3 and 4. In this case, the core 8 is supported by two opposing cups 9 and 10. Cups 9 and 10 are centrally located on both sides of the core. Since the core has a convex side and a concave side, the cup 9 supports the convex side of the core with its concave side,
Moreover, the cup 10 supports the concave side of the core with its convex side. The cup 9 is supported on the rod 11 by a substantially U-shaped member 12 which is fixed to the cup and to the rod 11. Similarly, cup 10
is supported on the rod 13 by a substantially U-shaped member 14 fixed to the cup and to the rod 13. Since the outer diameter of the cup is smaller than the outer diameter of each core 8, the outer periphery of the core is exposed. Alternatively, as shown in FIG.
It may have a small hole 15 formed in the outer periphery for receiving a wire hook 16 which is suitably connected to the support frame 17. Also, as shown in FIG. 6, instead of hooks, thin wires 18 can be passed through the holes 15 into the cores 8, and the wires 18 can be suitably connected to the support frame 17. can. FIG. 9 shows an enlarged cross-sectional view of a lens constructed according to the present invention. The lens and mounting structure is indicated generally by the reference numeral 30 and includes a lens body 31, an ultra-thin coating 32 and laterally extending horizontal loops 33, 34. Loops 33 and 34 are embedded in lens body 31, which may be constructed of plastic or other biologically acceptable material. Lens body 31 is pre-shaped or polished to have a predetermined focal length. The lens body 31 is made of poly(methyl methacrylate) (PMMA) impregnated with a UV absorbing substance such as Uvinol (registered trademark).
Preferably, it consists of: The ultra-thin coating 32 is applied or polymerized using a suitable plasma reactor, as will be described below. The lenses 30 to be coated can be prepared for insertion into the plasma reactor by placing the individual lenses on a frame 40, as shown in FIG. The frame 40 has an open rectangular loop shape, and each lens 30 has an open rectangular loop shape.
are tied to frame 40 by wire 41 or other means. Frame 40 is preferably made of stainless steel, and individual tie wires 41 may also be made of stainless steel. This wire 41 is fluxed through the individual loops 33 and 34 of the lens 30. The width of the frame 40 is predetermined, and when inserted into the reaction tube 101 of the plasma reactor, it is kept horizontally along the diameter of the tube 101, as shown in FIG. It's starting to become easier. The present invention will be explained below with reference to Examples. Example 1 A core in the shape of a corneal contact lens was produced from poly(dimethylsiloxane) in a conventional manner.
This core was placed on the support shown in FIG. The support is housed in four openings in an aluminum disk 19, as seen in FIGS. 7 and 8. The disc 19 is rotatably supported on a bar 20 such that it passes between two opposing electrode plates 21 and 22. Assemble the assembly shown in Figure 7 with a bell
It was placed in a plasma reaction chamber constructed as a jar vacuum system. After the bell jar was evacuated to a vacuum below 10 ^-3 Torr, methane and perfluoromethane (tetrafluoromethane) were introduced into the vacuum system using appropriate valves. The valve was adjusted to use a 50% mixture of methane and perfluoromethane. A flow rate of 5 cm ³ per minute was maintained under 1 atmosphere and a system pressure of 20 mTorr was used. After a steady state flow of methane and perfluoromethane was established, the discharge was started with a 10KHz power supply. The electrodes are equipped with magnets behind them to produce a stable glow discharge under these conditions. The voltage of the power supply was adjusted to maintain a constant discharge current of 300 mA. Discharge continued until the thickness monitor read a predetermined thickness. After coating was completed, the core was mounted on the support shown in FIG. The support held the core in the center, leaving the periphery free, and subjected to a second coating step to coat the periphery that was not covered because it was covered by the support in the first coating step. The second coating step is otherwise the same as the first coating step. During this discharge, due to the HF extraction step, the resulting polymer coating contained a small amount of fluorine atoms and the surface was sufficiently hydrophilic to ensure good wettability to the tear fluid of the eye. This polymer coating is
It had extremely tight crosslinks, resulting in a lipid-impermeable barrier due to its graphitic structure. Example 2 The coating was applied in the same manner as described in Example 1, but using a gas mixture of 50% tetrafluoroethylene and 50% hydrogen. Immediately after the deposition step, this coating was further treated with oxygen plasma for 2 minutes under the same discharge conditions as those used for polymer deposition. The resulting lens had an excellent lipid-impermeable barrier with a highly wettable surface. Example 3 The reaction tube 101 was sealed, and a vacuum pump (not shown) attached to one end of the reaction tube was operated to evacuate the reactor 101 to a pressure of 10 ^-3 rule or less. While keeping the valve provided between the vacuum pump and the reaction tube fully open, one of the valves (not shown) provided at the other end of the reaction tube is opened to supply air from the source to the reaction tube 101. Methane gas was introduced.
The pressure inside the reaction tube 101 was controlled by adjusting a flow rate measuring valve (not shown) provided between the reaction tube and the valve group so that the pressure was 25 millitorr.
The flow rate measuring valve is adjusted so that the methane gas flow rate is ^0.5cm3
It was adjusted to a value of STP/min. After the pressure and flow rate reach a steady state, a gas plasma is generated within the reaction tube 101.
The voltage of the RF source was increased. In this example, 13.5MHz
A radio frequency source was operated at a frequency of
RF energy is coupled capacitively to the electrodes and inductively through the coil of the RF source. The discharge within the reaction tube 101 was continued until a predetermined coating thickness of 0.1 nm was reached. The thickness of this coating is determined by a quartz crystal thickness monitor placed near lens support 40. The method described in this example resulted in a uniform coating on the lens 30 with a slightly brownish hue. Antireflective Coatings Intraocular lenses can be encapsulated with coatings that act as a barrier to surface penetration of chemicals as well as antireflective coatings. The reflectance from the surface at normal incidence is given by: R=Ns−No/Ns+No〓 ² 〓 ² where R is the reflectance and Ns is the refraction of the solid surface of the lens body 31 in contact with the aqueous humor having a refractive index No=1.336 in the eye. rate. Ns=
For a 1.490 poly(methyl methacrylate) intraocular lens, this equation gives a reflectance of 0.3% at each aqueous-lens interface. Antireflection coatings use interference phenomena to reduce this reflectance. In a single-layer anti-reflection coating, the thickness of the non-absorbing coating is 1/4 of one wave quantity (λ/4), and the refractive index of this layer is the magnitude of the reflectance at the aqueous humor-coating layer interface. is a refractive index that is the same as the reflectance at the coating-lens interface. In this case, the reflectance for a wavelength with an angle of incidence of 0 is 0 (here, the angle of incidence is defined as the angle between the normal to the lens surface and the incident ray).
The angle of incidence is 0 for a layer with a thickness of 1/4 wavelength (λ/4)
In the case of , the reflectance is given by the following equation. R _/4 = N ₁ ² −NoNs/N ₁ ² +NoNs where the subscripts o, ₁ , and s refer to the aqueous humor, the antireflection coating layer, and the solid (lens) surface, respectively. Therefore, the necessary condition for the reflectance to be 0 is N ₁ =√. From this equation, N ₁ =1.41 for a poly(methyl methacrylate) lens in the aqueous humor. Considering that the average wavelength of visible light is 500 nm, the antireflection coating for the intraocular lens 30 is made of a material with a refractive index N ₁ = 1.41 with a thickness of λ/4.
= 125 nm.
Since most hydrocarbon polymers have a refractive index near 1.50, a polymer with a fairly low refractive index must be deposited. A plasma polymerized film of tetrafluoroethylene has a refractive index N=1.42.
Therefore, a plasma polymerized film approximately 125 nm (0.125 microns) thick should provide an ideal antireflective coating. The performance of the polymer film on lens 30 can be significantly enhanced by using a device such as that shown in FIGS. 12-14. In Figures 12 and 13, two views of the equipment used in a bell gear (not shown) to obtain the plasma polymerized coatings of the present invention are shown. This device includes a rotatable substrate plate 50, a pair of parallel electrodes 5
1 and 52 and magnetic poles 53 and 54. The disk 50 is illustrated in more detail in FIG.
This disc has four rectangular openings 55, 56, 57
and 58. The lens to be coated is placed in substantially the same manner as described above for frame 40, as shown in FIG. The disk 50 is mounted in parallel relationship between electrodes 51 and 52 and is adapted to rotate slowly about an axis 59 by a motor (not shown) and a pair of magnets. The magnetic poles 53 and 54 are the electrodes 51 and 5.
It is placed directly behind 2. As can be seen from FIG. 12, the north pole 54 has a rectangular frame shape, and the south pole 53 has a circular magnetic pole face at the center of the rectangular frame 54. The magnetic field generated by these magnetic poles 53 and 54 influences the movement of electrons between the electrodes 51 and 52 when a potential is applied between the electrodes. In the set magnetic field and in the electric field applied between the electrodes 51 and 52, electrons move between the electrodes, taking a spiral or helical path.
This increases the mean free path of the electrons and increases the probability of collision with gas molecules existing between the electric circuits 51 and 52. The increased frequency of collisions with gas molecules allows the system to operate at lower pressures, which in turn gives a more uniform coating on the lens surface. Example 4 A number of lenses 30 are placed in openings 55-58 on a substrate disk 50 in the manner described above, and the disk 50 is placed between electrodes 51 and 52. Bell
The jar was evacuated to a pressure of less than 1 millitorr. Add tetrafluoroethylene to this system at 10.5
It was introduced at a rate of cm ³ (TP)/min. RF or
The AF (audio frequency) power supply was operated at 10KHz, and the discharge output was 18 Watts. The plasma discharge generated within the bell jar was maintained continuously and the thickness of the coating on the lens surface was controlled by a quartz crystal thickness monitor (not shown). This thickness also allows for rotating disks comparable to stationary monitors.
Adjustments were made using a calibration curve for the accumulation amount above 0. Coating continued until the thickness was 120 nm. The lens coating produced according to this example is highly hydrophobic, which further improves the wettability of the lens surface by aqueous body fluids.
It can be improved. Example 5 A lens 30 was prepared according to Example 3 or 4. At the end of a given coating process, the flow of monomer to the system was stopped and the remaining monomer in the bell jar was evacuated to a pressure of less than 1 millitorr using a vacuum pump. Each valve was opened to introduce an atmosphere of oxygen and argon. The pressure of the system was adjusted to approximately 50 mTorr by introducing a 50/50 mixture of oxygen and argon. The voltage of the power supply was increased, and the previously coated lens surface was irradiated with oxygen plasma for about 1 minute. This treatment results in a highly wettable surface without changing the overall properties of the thin coating previously applied according to Examples 1 or 2. The above examples demonstrate a preferred method of manufacturing an intraocular lens using the above apparatus and vapors of the above chemical composition. It should be understood that other hydrocarbon vapors other than methane may be used with acceptable results. Such accessory hydrocarbons include ethane, ethylene, acetylene, cyclohexane and benzene. Other perfluorocarbons other than tetrafluoroethylene can also be used. Such compounds include hexafluoroethane, tetrafluoromethane, perfluorocyclohexane, perfluorobenzene, and perfluorobutyne. It should be understood that basic lens materials other than poly(methyl methacrylate) can also be used, such materials include polystyrene, polycarbonate, polyvinyl chloride, and silicone polymers. The selection of this basic lens material is not as important as the matching of refractive indices to achieve a given result. Described and claimed herein is an improved intraocular lens formed from a transparent plastic material and encapsulated with a thin impermeable coating formed by plasma polymerization. The coating formed on the lens is relatively inert and effectively prevents unreacted or present free monomer, or monomer generated by the incident ultraviolet radiation, from penetrating into the plastic material of the lens. The coating thus formed also prevents the lens from adhering to the cornea or other parts of the eye during the implantation procedure. Plasma polymerization coatings can be further modified to form anti-reflective coatings, thereby preventing glare from the interface between aqueous body fluids and the lens surface within the eye. Animal Experiments The effects of the lens coating of the present invention on rabbit corneas were estimated. Coating with methane as well as its surface modification was found to reduce endothelial cell damage. Control, ie, uncoated lenses, produced an average of three times more damage than coated lenses in various experiments. The resolution of the lens was measured before and after coating, and it was found that there was almost no change.

[Brief explanation of the drawing]

1 is a front view of a support device for supporting a plurality of lenses in a discharge device, and FIG. 2 is a side cross-sectional view taken along line 2--2 of FIG. 3 is a front view of an improved support device, FIG. 4 is a side sectional view taken along line 4--4 of FIG. 2, and FIG. 5 is a front view of another improved support device. , FIG. 6 is a front view of another improved support device, FIG. 7 is a side view of a support for a plurality of lenses on a disk, and FIG.
7 is a front cross-sectional view taken along line 8--8 of FIG. 7, FIG. 9 is an enlarged cross-sectional view of an intraocular lens coated with the method of the present invention, and FIG. 11 is a plan view of a rectangular frame for mounting an intraocular lens for insertion into a reactor; FIG.
10 is a partial perspective view of the frame of FIG. 10 installed in a plasma reactor; FIG. 12 is a view of an alternative arrangement for installation in a Bell-Jer reactor; and FIG. , line 13-13 in FIG.
FIG. 14 is a side view taken along the
13 is an enlarged plan view of a rotatable disk suitable for use with the apparatus of FIG. 12; FIG. Reference 1 Reference: Galin: Academy meeting, Kansas City, Mo. 2 Herman, MF and Becares, N.
(Herman, MFand Bekales, N.), Encyclopedia of Polymer Science and Technology.
Polymer Sciences and Technology), New York, Interscience, 1965, No. 1
Luskin, LSand Meyers, RJ, Vol. 246-328.
Author, Acrylic ester polymer
polymers). 3. Dangerous Properties of Industrial Materials, edited by Sax, NI.
of Industrial Materials), 4th edition, New York, Van Nostrand,
Reinhold, 1975, 924 pages. 4 Spielman, CR, Main, RJ, Haag, HO and Larson, PS (Spealman, C.
R., Main, R.J., Haag, H.O. and Larson,
PS), Methyl methacrylate monomer: studies on toxicity (Monomer
methylmethacrylate: Studies on Toxicity),
Ind.Med., 14 , 292, 1945. 5 Boume, WM, Kaufman, HE (Boume,
WM, Kaufman, HE), Endothelial damage associated with intraocular lenses.
associated with intraocular lenses), Am.J.
Ophthalmol., 1 , 482-485, 1976. 6 Katz, J., Kaufman, HE, Goldberg, EP and Sheets, JW (Katz, J.,
Kaufman, H.E., Goldberg, E.P., and
Sheets, JW), Prevention of endothelial damage due to intraocular lens insertion.
damage from intraocular lens insertion),
Trans, Am.Acad.Ophthalmol.and
Otolaryngol., 83 , 204–211, 1977. 7 Kirk, S., Burde, RM, and Waltman, SR.
Waltman, SR), Minimizing corneal endothelial damage due to intraocular lens contact.
endothelial damage due to intraocular lens
contact), Invest.Ophthalmol., 16 (11), 1053−
1056, 1977. 8 Main Star, MA (Mainster, MA),
Am.J.Ophthalmol., 85 , 167−170, 1978.

Claims (1)

[Claims] 1. An ultra-thin, optically transparent, lipid-impermeable product comprising a reaction product obtained by a plasma polymerization method carried out in a gas atmosphere using a magnetically enhanced electrode system. A soft corneal contact lens constructed of a soft, highly oxygen permeable polymeric lens with a barrier coating formed on its surface;
the atmosphere is essentially nitrogen- and oxygen-free and contains (a) hydrocarbons, (b) halogenated hydrocarbons, (c) halogenated hydrocarbons and hydrogen, (d) hydrocarbons and elemental halogens, and (e) A soft contact lens comprising at least one substance selected from the group consisting of mixtures thereof. 2. The soft contact lens of claim 1, wherein the polymer lens comprises a silicone polymer. 3. The polymer lens is made of silicone polymer,
A soft contact lens according to claim 1. 4. The soft contact lens of claim 1, wherein the polymer lens comprises polyurethane. 5. The soft contact lens according to claim 1, wherein the polymer lens is made of polyurethane. 6 One thing is methane, ethane, propane,
A soft contact lens according to claim 1, which is selected from the group consisting of butane, pentane, ethylene, propylene, butylene, acetylene, cyclohexane, cyclohexene, benzene and pentane. 7. The soft contact lens of claim 1, wherein one is a saturated hydrocarbon. 8. The soft contact lens according to claim 1, wherein the halogenated hydrocarbon is a saturated halogenated hydrocarbon. 9. The soft contact lens according to claim 1, wherein the halogenated hydrocarbon is a fluorinated hydrocarbon. 10. The soft contact lens of claim 1, one of which is a mixture of methane and tetrafluoromethane. 11. A soft contact lens according to claim 1, wherein one is selected from tetrafluoromethane, hexafluoroethane and tetrafluoroethylene. 12 (a) preparing a soft, oxygen-permeable polymeric lens; (b) placing the lens in a plasma polymerization apparatus having a magnetically enhanced electrode system; and (c) essentially containing nitrogen as well. Contains no oxygen and is composed of (1) hydrocarbons, (2) halogenated hydrocarbons, (3) halogenated hydrocarbons and hydrogen, (4) hydrocarbons and elemental halogens, and (5) mixtures thereof. (d) subjecting the gas atmosphere to a discharge under conditions sufficient to generate plasma to polymerize the one material and the lens; Forming a lipid-impermeable, highly oxygen-permeable, optically clear barrier coating on a lens surface, the reaction product being a lipid-impermeable, highly oxygen-permeable, optically clear barrier coating. 13 further introducing oxygen into the apparatus and subjecting the oxygen to an electrical discharge under conditions sufficient for the oxygen to generate a plasma to cause a reaction between the oxygen plasma and the coated lens; 13. The method of claim 12, further comprising the step of increasing the hydrophilicity of the coated lens thereby. 14. The method of claim 12, further comprising the steps of introducing argon and oxygen into the apparatus and treating the argon and oxygen under conditions sufficient to generate plasma. . 15. The method of claim 12, wherein the lens comprises silicone. 16. The method of claim 12, wherein the lens comprises polyurethane. 17 Formed on an intraocular lens made of plastic material by plasma polymerization using a magnetically reinforced electrode system in a gaseous atmosphere, provided that the atmosphere does not essentially contain nitrogen or oxygen. figure,
and at least one selected from the group consisting of (a) hydrocarbons, (b) halogenated hydrocarbons, (c) halogenated hydrocarbons and hydrogen, (d) hydrocarbons and elemental halogens, and (e) mixtures thereof. made of plastic, completely encapsulated within a thin, inert, impermeable coating that is effective in preventing the leakage of monomers and other chemicals from within the body of the intraocular lens. Improved intraocular lens. 18. The lens of claim 17, wherein the front lens body is impregnated with an ultraviolet absorbing substance. 19. The lens of claim 17, wherein the coating is formed to a thickness of about 120 nm to form an anti-reflective coating on the lens.