EP1139857A2 - System and method for the non-contacting measurement of the axis length and/or cornea curvature and/or anterior chamber depth of the eye, preferably for intraocular lens calculation - Google Patents

Abstract

The invention relates to a combination apparatus for determining in a non-contacting manner the axis length (AL), anterior chamber depth (VKT) and cornea curvature (HHK) of the eye, notably for the calculation and selection of an intraocular lens (IOL) to be implanted.

Description

Title:

Arrangement and method for contactless measurement of the axis length and / or the corneal curvature and / or the anterior chamber depth of the eye, preferably for IOL calculation.

In Fig. 1, a longitudinal section through the human eye is shown schematically. The axis length AL of the human eye is usually measured using ultrasound using the contact method.

Other measurement methods are described in DE 3201801 and US 5673096, DE 4446183 AI. The curvature of the corneal radius HHR is determined using known keratometers / ophthalmometers (DD 251497, US 4572628, US 4660946, US 5212507, 5325134). The anterior chamber depth VKT can be measured by means of ultrasound or by means of an additional unit for a slit lamp (anterior chamber depth meter, adjustment via the slit lamp image).

In particular before a cataract operation, but also when monitoring the course of school myopia and determining the aniseicon, these parameters must be determined, which are also important for the selection of the IOL intraocular lens to be implanted. In clinical practice, it is common to use these devices at least with two devices ( eg ultrasound a-scan and automatic keratometer) to be measured. The measured variables are used in formulas which calculate the optical effect of the IOL. Depending on the type of device used, there may be various errors that affect the selection of the IOL.

The object of the invention is to reduce these device-dependent measurement errors to a minimum.

The object is achieved by the features of independent claims. Preferred developments are the subject of the dependent claims.

According to the invention, all the necessary parameters of the eye are advantageously determined by means of a device arrangement and corresponding measuring methods. Necessary settings that enable the device to be adjusted to the patient are also implemented in this arrangement.

The calculation of the IOL is also carried out using this device arrangement. This also eliminates data loss or data falsification when the measured values are transmitted from various devices to the computer which carries out the IOL calculation. The invention and its advantages are explained below with reference to the schematic representations.

The schematic structure of the device is shown in Fig.2.

To measure the axis length, the light of a laser diode 1 is adjustable via a Michelson interferometer (3-5), consisting of a fixed reference arm R1 with a reflector 4, here a triple prism and one based on different positions of a further reflector 5 (triple prism) Reference arm R2, and a beam splitter cube 3 for superimposing the radiation components reflected in Rl and R2, a splitter cube 8 and a diffractive optical element DOE 9 are imaged on the patient's eye 14. A diode 7 monitors the light output of the laser diode 1. The partial beams reflected by the cornea and retina of the eye 14 overlap and are divided by means of DOE 9, divider cubes 8, which has a lambda / 4 plate Pl for rotating the polarization plane, divider cubes 15 with a lambda / 2 plate P2 via a focusing element, here an achromatic 16 mapped onto an avalanche photodiode APD 17. The axis length measurement is carried out according to known methods, for example described in US5673096.

To observe the eye and the resulting reflexes, part of the reflected light (light coming from the eye) is applied to a CCD using an achromatic lens 22 via mirror 20.

Camera 23 shown.

Achromats 18, 19 are swung out here.

An aperture 21 is in the switched-off position.

To measure the corneal curvature HHK, the eye 14 is illuminated analogously to DD 251497 at an angle of approximately 18 ° to the optical axis AI by means of 6 preferably infrared LEDs ^Λ s 10, two of which are shown in FIG. 1 by way of example in the plane of the drawing are shown. Pinhole diaphragms 10 a are arranged downstream of the LEDs for generating point-shaped lighting images.

To collimate the diode light, six lenses 11 are arranged downstream of the LEDs in the direction of illumination. The images of these light sources created in the eye (as a reflex of the cornea) are imaged on the CCD camera via divider cubes 8 and 15 and achromats 18 and 19. The DOE 9 is advantageously pivoted out here, but can also remain in the beam path. The achromat 22 is pivoted out.

To determine the VKT, each eye is LED at an angle of approx. 33 °

12, slit diaphragm 12a and cylindrical lens 13 illuminated in the form of a slit.

The resulting scatter images of the cornea and front surface of the lens are over

Divider cubes 8 and 15 and achromats 18 and 19 are imaged on the CCD camera 23 with the DOE preferably pivoted out.

The achromat 22 is pivoted out.

3 shows a front view of the device in the direction of the observation, with the illustration of a known slit lamp cross table for x y / z adjustment being dispensed with.

You can see the DOE 9 (at its center AI indicates the position of the optical axis in the device), the lenses 11 for the determination of the corneal curvature with an invisible LED 10 behind it, the cylindrical lenses 13 for the slit image for measuring the VKT and six IR diodes 24 for illuminating and adjusting the eye 14.

4, the measurement tasks are to be explained in more detail with the aid of the beam path A-D from the eye 14 to the CCD camera 23.

Beam path C: adjustment of the device to the eye

The eye is at the focal length of Achromat 18, is imaged to infinity and is imaged via Achromat 22 in the plane of the CCD camera. Achromat 19 is swung out here. The patient is offered a fixation light by means of a laser diode (LD) or LED 1 so that he can align the eye pupil in the direction of the optical axis. It is necessary to image a larger section of the eye 14 (for example 15 mm) on the CCD camera. The

Due to its low efficiency (approx. 5% in the focusing part) DOE is for the

Image of the iris structures less suitable, so that an optical system with a fixed

Image scale, consisting of achromats 18 and 22 realizes the image.

The DOE is preferably swung out.

In order not to create additional fixation incentives for the patient, the eye 14 is illuminated by means of IR diodes 24 (FIG. 2) (e.g. 880 nm), which are preferably characterized by a broad radiation characteristic (large half-value angle).

The device is adjusted to the patient via the well-known slit lamp cross table, which can be adjusted in the x, y, z direction.

For example, a VCM 3405 from Phillips can be used as the CCD camera.

Illumination of the eye is necessary in order to be able to adjust the patient to the device even in darker rooms.

This illumination should be as diffuse as possible for a field of 15 mm, but an image of the light source through the cornea cannot be avoided (since the cornea acts as a convex mirror).

The basic idea here is to advantageously use the means for lighting to adjust the patient's eye at the same time.

Six infrared LEDs 24 with a relatively large half-value angle are arranged on a circumference (possibly the same circumference as in the keratome measurement). These create 6 points on the cornea, which are imaged on the CCD camera.

The patient's eye is shown live on an LC display or monitor; In addition, a circle / crosshair is shown on the LCD / monitor for center marking. To position the eye, the 6 points must be set centrally to the circle shown - this is done by moving the cross table; the patient is correctly adjusted in height / side / depth when the points can be seen in the center and in focus. The patient himself looks into the device - from there an alignment laser 1 or LED la is projected, onto which the patient has to fixate. The laser reflex can be seen in the middle of the pupil. An additional setting aid should be shown on the LC display / monitor.

For the detection of the interference signals of the axis length meter, an avalanche is

Photodiode APD provided.

When the patient's eye is on the optical axis of the measuring device, the alignment laser 1 or LED 1a is reflected by the anterior surface of the cornea; the reflected light is reflected on the

APD pictured. This generates a DC voltage signal from the APD

(Relative) height represents a measure of the centering of the patient's eye.

This DC voltage signal is fed to the internal computer via an A / D converter and from there is displayed in a suitable form (eg a bar / circle) on the LCD.

The operator is thus provided with further information on the adjustment state of the patient's eye by the different size of the bar / circle.

Beam path D: ALM

The reflections of the laser diode 1 (e.g. 780 nm) are imaged on the CCD camera 23 via the DOE as a parallel beam path and the achromatic lens 22, an eye segment of approximately 5 mm being shown with the optics 18, 19 pivoted out for observation and reflex adjustment. In order to transmit a maximum energy to the APD 17, a large part, advantageously more than approx. 80-95% of the total energy, is coupled out to the APD on the divider cube 15 shown in FIG. 2; only about 20 - 5% of the light falls on the CCD camera.

Beam path B: keratometer

Illumination is preferably carried out analogously to DD 251497 by means of six IR diodes 10 (e.g. 880 nm) in order not to impede the fixation of the patient's eye 14 to the fixation light of the LD 1 or the LED 1a.

The predetermined resolution of the CCD camera 23 requires the imaging of a field no larger than approx. 6 mm on the eye 14 in order to achieve a measuring accuracy of 0.05 mm. The effect of the DOE is preferably switched off again by swiveling out and the achromats 18 and 19 realize the 6 corneal reflex images. Serve to increase a measuring accuracy largely independent of the distance between the patient's eye and the device

a telecentric aperture 21 which limits the aperture for the measurement to preferably less than 0.05 and

- Collimators 11 located between the LED and the patient's eye, which keep the angle of incidence constant irrespective of the axial position of the patient's eye.

The LED light is advantageously imaged via a pinhole 10a, which enables an exact adjustment of the keratometer measurement points. The focal length of the collimator should be more than 50 times the effective light source extension in order to achieve the desired measuring accuracy of the radius measurement regardless of the position.

Beam path A: VKT

Since light scattering plays a decisive role in the observation of light sections in the human eye, the shortest possible wavelength must be used to illuminate the eye 14

Light source can be selected (e.g. 400 - 600nm).

When determining the VKT, the required measurement accuracy of

0.1 mm, a field no larger than approx. 6 mm is imaged on the eye 14 on the CCD camera 23.

Bypassing the DOE effect or when the DOE is swung out, this is done by the

Achromats 18 and 19 realized. Achromat 22 is swung out.

The telecentric aperture 21 pivoted or adjusted here must be larger

Have diameters (for an aperture of preferably greater than 0.07 - e.g. 13mm) to the

To only minimally reduce the light intensity of the faint light scattering images that arise during the VKT measurement. It can therefore be adjusted in at least two positions or exchanged for a second screen.

The subject's eye is illuminated laterally at a fixed angle through the bright light gap. The resulting light cuts on the eye are visualized

System 18, 19, 21 imaged on the CCD camera. Illumination and observation form a fixed angle, preferably approximately 33 °.

8a, b schematically shows the arrangement for determining the VKT, in Fig. 8a

Illumination direction and in Fig.δb the detection direction. The light gap is formed by a row of bright LEDs 12, which have a defined one

Have a distance to a gap of fixed width 12a.

The gap 12a illuminated in this way is imaged by a cylindrical lens 13 as a gap image S on the subject's eye.

The LEDs used typically have a lifespan of at least

10,000 hours. (In comparison: halogen lamp 100-200 hours).

There are no signs of wear due to high temperature loads like one

Halogen lamp.

The subject's eye is imaged with the relevant image sections via a schematically illustrated imaging optics 18, 19, preferably on a CCD sensor 23.

The mapping is carried out telecentrically - telecentric aperture 21 to the influence of the

Minimize subject adjustment. The video signal is on a monitor or LC

Display shown so that the operator can carry out the subject adjustment and measurement in a relaxed position.

The measuring method is not based on the measurable shift of partial images; the pupil division can thus be omitted.

The signal from the CCD camera 23 is stored in the memory of the

Computer C taken over.

With the help of suitable image processing software, distances in the sectional image are determined, from which the VKT (accuracy 0.1 mm) is calculated.

An improvement in the relevant image content (for example by switching off ambient light) is achieved by switching the lighting LEDs on and off in a suitable form, synchronized with the video fields.

An achromatic lens with a defined focal length is sufficient to image the eye on the CCD camera. The focal length is determined depending on the desired image section on the eye that is to be imaged.

The aperture 23, which fulfills the telecentric condition, is arranged in the image-side focal length of the achromatic lens.

This simple structure of the imaging system ensures that it can be easily integrated into other systems.

A fixation light 1.1a (LED) is faded in via beam splitter 8 in FIG. 8b. A light source is integrated in the observation system (e.g. LED la or laser diode 1, on which the test subject is fixed.

The video signal from the camera is shown on a monitor or LC display.

During the adjustment and measurement of the test person, the operator can convince himself that the test person is correctly fixed - and thus the measurement result is unadulterated.

The gap illuminated in this way is placed on the test person's eye through a cylindrical lens

(4) shown.

A picture of a 0.3 mm wide slit with an aperture greater than 0.1, and the use of white light LEDs, which turned out to be slightly different from a 1: 1 picture, proved to be particularly advantageous.

The subject's eye is imaged with the relevant image sections via imaging optics 18, 19, preferably on a CCD sensor 8. The imaging is carried out telecentrically in order to minimize the influence of subject adjustment. The video signal is displayed on a monitor or LC display, so that the operator can carry out the subject adjustment and measurement in a relaxed position.

The signal from the CCD camera is e.g. into the memory of a

Computer.

With the help of suitable image processing software, distances in the sectional image are determined, from which the VKT (accuracy 0.1 mm) is calculated.

An improvement in the relevant image content (e.g. by switching off ambient light) is achieved by synchronizing the lighting LED in a suitable form

Video fields are clocked on and off.

7 shows how the VKT is determined on the basis of the image on the CCD matrix.

The image of the eye, which is captured by the CCD camera, is shown with the reflection image FI of the adjustment laser or the fixing LED, and the scattered light SH of the cornea and the lens SL when the illumination 1 is switched on. Determination of the distance between the leading edges of the scatter images of the cornea and lens in digitized images

The starting point of the image processing is (n times) a pair of images taken immediately after one another: image 1 with the slit illumination switched on ("bright image"), image 2 without slit illumination with the image of the fixing lamp ("dark image"). The processing takes place in the following essential steps:

• Detection of the pupil in the dark image: histogram-based selection of a threshold value for binarization taking into account boundary conditions. Determination of an ellipse circumscribing the pupil by evaluating the covariance matrix of the binary image.

Detection of the fixation point in the pupil in the dark image: determination of all connected regions whose gray values lie above the 0.9 quantile of the gray value distribution in the dark image. Determination of a probability measure for each region, which depends on the area, shape and distance from the center of the pupil. Selection of the focus of the most likely region as a fixed point.

• Calculation of the difference image (light image minus dark image) and noise suppression in the difference image by median filtering

• Determination of the edge profile of the scatter images of the slit lighting in the difference image: histogram-based selection of a threshold value for binarization taking into account boundary conditions. Rough detection of the edges as the location of the threshold value being exceeded in a predetermined area around the fixing point. Fine detection of the edges as the location of the turning point of the gray value curve in the line profile that is closest to the roughly detected position. Elimination of reflex edges by outlier detection in the edge course (removal of a predetermined proportion of points which is furthest from the middle edge course).

• Determination of the distance X of the front edges of the corneal and lens scattering image SH, SL (in pixels): Approximation of the edge profile by means of ellipses (restricted minimization of the square error sum). Calculation of the distance of the intersection of these ellipses with the horizontal through the fixation point.

Calculation of the anterior chamber depth from the above Distance:

Conversion of the distance X in mm in mm (image scale of the optics and pixel size of the CCD matrix are included) r = corneal radius, n = refractive index of the aqueous humor, ω = angle between illumination and observation

This formula applies exactly when the image of the fixing lamp is at the front edge of the lens scattering image, as shown in FIG. 7; otherwise the distance of the fixation lamp image from the front edge of the lens scatter image can be determined and from the amount of this "decentering" a correction value for the anterior chamber depth can be determined according to known imaging formulas.

The corneal radius is preferably measured using the keratometer device described above.

The following is a summary of characteristic settings, which must be observed when combining the 3 required measured values and the adjustment process:

ALM Kerat VKT adjustment

Field size approx.15mm approx.5mm approx.6mm approx.6mm

Wavelength IR (e.g. 880nm) e.g. approx 780nm IR (e.g. 880nm) VIS (e.g. 400-600nm)

Beam aperture swung out swung approx. 6 mm approx. 13 mm

DOE without effect works without effect without effect

(swung out) (swung out) (swung out)

As can be seen from this overview, different wavelength ranges are used for the different measuring tasks. The divider cubes 8 and 15 come here are of great importance because the lighting, observation and measuring beam paths are separated from each other at these points.

Special divider layers realize this task taking into account the linear

Polarization of the laser diode 1.

Divider cube 8:

The laser light coming from the interferometer should be reflected at most in the direction of eye 14; the laser light coming from the eye 14 should have maximum transmission.

In addition, the divider layer in the cube 8 for the IR and VIS light components

Keratometer and VKT measurements have maximum transmission.

Since the LD 1 (for example LT 023 Sharp) is linearly polarized light, a dielectric multilayer with a polarizing effect can preferably be used

Come into play. The characteristic transmission curve is shown in Figure 4.

The vertically polarized light coming from 1 (s-pol, 780 nm) is reflected as far as possible (approx. 98%).

Circularly polarized light is generated by the Lamba / 4 plate. The light reflected by the eye 14 is thus linearly polarized again after passing through the lambda / 4 plate; however, the direction of polarization is rotated by 90 ° (parallel polarized, p-pol). For this

At 780 nm, the dividing layer exhibits approximately 100% transmission in the direction of vibration.

The IR and VIS LEDs emit unpolarized light.

As can be seen from Fig. 6 a, the transmission of the divider layer is in the

Wavelength range from 420 to 580 nm and in the range from 870 to 1000 nm greater than 90% for unpolarized light.

Structure of the layer: divider cube 8:

In addition to its normal function - high pole dividing effect in a defined wavelength range - this pole dividing cube fulfills the additional requirements of high transmission in the visual wavelength range (420 ... 560nm) and in the near infrared range (870 .... 1000nm).

The layer design meets these requirements for a narrow angle of incidence around 46 °. The materials used are in terms of refractive index substrate, putty index and Refractive index of the coating substances matched to one another. The following materials were selected for this special application: Substrate: SF2 n = 1.64

Putty n = 1.64

H n = 1.93

L n = 1.48 The design consists of 17 alternating layers H L. HFO2 is H, SIO2 is L.

For comparable dividers, suitable dividers can be produced by a suitable choice of the refractive indices of the substrate and coating substances and the angle of incidence.

Parameters: high transmission from 420 ... 560 nm, nonpol. high transmission of 870 .... 1000 nm, non-polar. Pole pitch 780 ± 20 nm

Example:

1 HFO2 156.8 nm

2 SIO2 118.1 nm

3 HFO2 166.4 nm

4 SIO2 95.8 nm

5 HFO2 160.2 nm

6 SIO2 147.3 nm

7 HFO2 145.6 nm

8 SIO2 151.0 nm

9 HFO2 144.9 nm

10 SIO2 148.2 nm

11 HFO2 149.2 nm

12 SIO2 139.9 nm

13 HFO2 161.3 nm

14 SIO2 103.9 nm

15 HFO2 179.5 nm

16 SIO2 64.9 nm

17 HFO2 170.9 nm Divider cube 15:

The laser light coming from divider cube 8 should be reflected to approx. 80-95% with approximately 20-5% transmission. The divider layer should have max.

Have transmission.

This layer is also implemented by means of a pole divider, the properties of which approximate the divider layer in FIG. 8. The lambda / 2 plate arranged on divider cubes 15 rotates the polarization direction of the incoming light by 90 °, so that the s-pol component falls again on divider cubes 15.

By modifying layer 8, the above Divider ratio set.

The transmission is greater than 90% for unpolarized light in the IR and VIS range.

Structure of the layer: divider cube 15:

This divider cube fulfills the requirements of the reflection s-pol of 80 ... 95% at one

Wavelength of 780nm ± 20 nm - the additional requirements of high transmission in the visual wavelength range (420 ... 560nm) and in the near infrared range (870 .... 1000nm)

(Fig. 6b).

The layer design meets these requirements for a narrow angle of incidence around 46 °.

The materials used are in terms of refractive index substrate, putty index and

Refractive index of the coating substances matched to one another. For that special

The following materials were selected:

Substrate: BK7 n = 1.52

Putty n = 1.52

H n = 1.93

L n = 1.48 The design consists of 13 alternating layers H L.

For comparable dividers, suitable dividers can be produced by a suitable choice of the refractive indices of the substrate and coating substances and the angle of incidence.

Parameters: high transmission from 420 ... 560 nm, nonpol. high transmission of 870 .... 1000 nm, non-polar. Reflection s-pole approx. 80..95% 780 ± 20 nm Example:

1 HFO2 130.2 nm

2 SIO2 215.4 nm

3 HFO2 130.6 nm

4 SIO2 17.8 nm

5 HFO2 160.7 nm

6 SIO2 241.6 nm

7 HFO2 136.6 nm

8 SIO2 240.0 nm

9 HFO2 156.4 nm

10 SIO2 18.0 nm

11 HFO2 135.1 nm

12 SIO2 214.1 nm

13 HFO2 131.3 nm

A central control is provided according to FIG. 5 for setting and controlling all adjustable units and optical elements such as optics 18, 19, 22, aperture 21, etc.

The various imaging scales, taking into account the effect of the DOE, require switching processes in the device. These are preferably motorized and program-controlled.

A compact device was implemented in which the essential electronic components are integrated.

The centerpiece is an embedded Pentium Controller C, to which a display D (display of the examined eye 14 and menu navigation for the operator), keyboard, mouse, foot switch and printer are connected as peripheral devices.

ALM

The control of the laser diode 1 and the interferometer slide IS (movable prism 5, connected to the measuring system) takes place via the controller C. To reduce the influence of eye movements, a short measuring time (less than 0.5 sec) must be implemented. The signal generated by the APD 17 arrives in a signal processing unit SE Dependence of the signal size amplified, then frequency-selective amplification and with a

Sampling frequency, which corresponds to about 4 times the frequency of the useful signal, converted from analog to digital. The digital samples are taken from the high-speed port HS of the Pentium platform.

There, digital signal processing takes place by means of Fourier transformation without an externally generated reference frequency.

The signal is shown on the display; the measuring system provides the associated

Axis length amount.

Keratometer

The controller C is connected to the control of the CCD camera 23 and the diodes 10.

During the adjustment process for measuring the corneal curvature, the diodes 10 are preferably operated in the continuous light mode in order to flicker those shown on the LCD

To prevent corneal reflex images.

During the measuring process, these diodes are switched on and off picture-wise; the

Controller C the diodes 10 in synchronism with the image pulse of the CCD camera 23, i.e. the

Diodes are on for one picture and off for the next.

After subtracting (forming the difference) two successive images, you get

In pairs, only the reflections from the cornea that were generated by the LED 10 and disturbing reflections from ambient light are switched off.

The reflex images created on the camera 23 are digitized using the frame grabber FG and stored in the RAM of the Pentium platform (

Controler C) filed.

This is followed by determining the center of gravity of the reflective images of the diodes using image processing and calculating the corneal radii using the approximate formulas described in DD 251497.

To increase the reproducibility of the measurement results, approx. 5 image series (each consisting of two fields with and without exposure by the synchronously clocked LED) are recorded per measurement process.

VKT

The controller C is still connected to the diodes 12.

During the setting process (adjustment), the diodes 12 are preferably operated in continuous light mode, similar to the keratometer. During the measuring process, the lighting diodes for the left and right eyes are optionally clocked by the controller (analogous to keratometers)

According to the operator's instructions, the device is moved to the left or right and adjusted to the center of the eye using ...

The edge position of the scatter images is determined by means of image processing

The VKT is calculated from the distance between the corneal and lens scattering images, as already described.

Approximately 5 series of images per measurement are also recorded.

lighting

The controller C is connected to the diodes 24.

The IR diodes 24 for illuminating the eye can be switched on at any time

Controllers can be switched on (controlled within the program or controlled by the operator)

The controller is still (not shown) with the controls for the input and

Swinging out / adjustment of the DOE 9, the lenses 18, 19, 22 and the diaphragms 21 connected.

The IOL is calculated using the internationally customary calculation formulas, which are stored in the device memory and can be called up, from the measured values AL, HHR, VKT and are printed out on a printer.

Claims

claims 1. Combination device for the contactless determination of the axis length (AL) and anterior chamber depth (VKT) of the eye or axis length and curvature (HHK) or corneal curvature and anterior chamber depth or axis length and anterior chamber depth and corneal curvature 2. Combination of a device according to claim 1 with the fixation of the eye via a fixation lamp and / or the illumination by light sources grouped eccentrically around the observation axis. Third Arrangement according to at least one of the preceding claims, wherein for imaging the eye on a camera and for generating different imaging scales, preferably pivotable imaging optics are provided in the beam path. 4th Arrangement according to at least one of the preceding claims, wherein telecentric diaphragms of different sizes, pivotable or adjustable, are provided in the beam path. 5th Arrangement according to at least one of the preceding claims, an interferometer arrangement having an adjustable path length difference being provided for the AL measurement. 6th Arrangement according to claim 5, wherein a preferably swing-out DOE is provided in the interferometer arrangement. 7th Arrangement according to claim 5 or 6, wherein the light source of the interferometer of the AL measurement or an additional light source coupled to the interferometer is used to fix the eye in the VKT measurement or HHK measurement. 8. Arrangement according to one of claims 5-7, wherein the Detection element of the arrangement for AL measurement for detecting the adjustment state of the Eye and for displaying the adjustment state of the eye is provided. 9th Arrangement for determining the VKT, preferably in a combination device according to one of claims 1-8, consisting of a slit-shaped beam which radiates in at an angle to the side of the eye Illumination via imaging optics 10th Arrangement according to claim 9, wherein an anamorphic imaging optics, preferably a cylindrical lens, is provided for the illumination. 11th Arrangement according to claim 9 or 10, with an illumination angle preferably in one Range around 33 degrees to the observation axis. 12th Arrangement according to one of claims 9-11, wherein the of different layers of the Eye-scattered light is recorded on a camera and the camera signal is evaluated. 13th Arrangement for determining the CHD, preferably in a combination device according to one of claims 1-12, consisting of 6 arranged concentrically and symmetrically Light sources. 14th Arrangement according to claim 13, with light sources in the IR range. 15th Arrangement according to claim 13 or 14, wherein the radiation of the light sources is collimated via optics. 16th Arrangement according to one of claims 13-15, with an illumination angle for Observation axis in a range of preferably around 18 degrees. 17th Arrangement for adjusting the patient's eye to the device, preferably in one Combination device according to one of claims 1-16, consisting of preferably six concentrically arranged light sources. Arrangement according to one of claims 13-17, wherein the light sources are arranged between the HHK light sources. 19th Beam splitter cube in a combination device according to one of claims 1-18, with a high transmission in the visual and / or near infrared range and for coupling the laser light coming from the interferometer for AL determination, a high reflectivity in the direction of the eye for the polarized laser light and a high transmission for the laser light reflected by the eye in the direction of detection. 20th Beam splitter cube according to claim 19, which has a lambda / 4 plate for generating circularly polarized light. 21st Beam splitter cube in a combination device according to one of claims 1-20, for coupling out the polarized laser light coming from the eye in the direction of a detector with a high reflectivity and a high transmission for the visible and / or near infrared range. 22. Beam splitter cube according to Claim 21, which has a lambda / 2 plate for rotating the direction of polarization of the polarized laser light 23. Beam splitter cube according to one of claims 19-22, with an alternating structure of a higher-refractive layer H and a low-refractive layer L. 24. Arrangement according to one of claims 1-23, wherein a common camera with a subsequent evaluation unit is provided for detecting and processing the position of the light source images of the VKT determination and the HHK determination and representation or detection of the adjusting light sources 25. Arrangement according to one of claims 1-24, with the representation of the illuminated eye and a user interface on a monitor. 26th Arrangement according to one of claims 1-25, with a central control for pivoting the DOE and / or the imaging optics and / or the diaphragms and or the interferometer adjustment and / or the switching on and off of the light sources for VKT determination and / or HHK measurement and or adjustment and / or AL measurement 27. Method for operating a combination device according to at least one of claims 1- 26, with the following sequence of measurements: first AL, then HHK, then VKT or first HHK, then VKT, then AL or first HHK, then AL then VKT. 28th Method for determining the HHK and / or the VKT, the lighting for image generation of the CCD camera being switched on and off in a synchronized manner. 29. 29. The method of claim 28, wherein the image is switched on and off. 30th Method according to one of claims 28 or 29, wherein pairs of images are produced illuminated / unilluminated and processed further. 31st Method for determining the VKT, in particular according to one of claims 1-30, with the following sequence • Detection of the pupil in the dark image • Detection of the fixation point in the pupil in the dark image. • Calculation of a difference image (light image minus dark image) and noise suppression in the difference image • Determination of the edge course of the scatter images of the slit lighting in the difference image. • Determination of the distance X of the front edges of the corneal and lens scattering image SH, SL (in pixels) • Calculation of the anterior chamber depth from the distance X. 32nd Arrangement for measuring sections of the eye, preferably for determining the Anterior chamber depth VKT, preferably according to one of claims 1-31, consisting of a slit-shaped illumination which illuminates the side of the eye at an angle to the observation axis, preferably via imaging optics, and a receiver arrangement which detects the scattering images coming from the eye with downstream signal processing. 33. The arrangement of claim 32, wherein the slit-shaped illumination is formed by a series of point-shaped light sources. 34. The arrangement of claim 33, wherein the light sources are white light LEDs 35. Arrangement according to claim 33 or 34, wherein the light sources in the direction of illumination Gap is subordinate. 36th Arrangement according to one of claims 33-35, wherein the imaging optics are anamorphic and is preferably a cylindrical lens. 37th Arrangement according to at least one of claims 32-36, wherein one Detection takes place using a CCD camera. 38. Method for operating an ophthalmic examination device according to one of the Claims 32-37, preferably for determining the VKT, the in the detection image The location of different scatter patterns is determined and a calculation of the Distance from sections of the human eye, preferably the Anterior chamber depth occurs.