Carl Zeiss Meditec Ag

Ferid Bajramovic

Tobias Bühren

Ralf Ebersbach

Martin Hacker

Matthias Reich

Martin Volkwardt

Peter Klopfleisch

Gerard Antkowiak

Wei-Jun Chen

Manfred Dick

Martin Kühner

Rico Fuchs

Michael Trost

Jörg Meissner

Tanja Teuber

Christopher Weth

Nino Hirnschall

Oliver Findl

Stephan Laqua

Akhil Ramesh Kumar

Joao Emanuel Goncalves Bras

Michael Zimmermann

Janine Feuker

Christian Platt

Tobias BÜHREN

Konrad SCHÖBEL

A device and method of compensating for the temperature dependence of a facet lens used for determining the topography of an eye. According to the invention, temperature sensors are present for determining the temperature of the facet lens. In addition, the temperature dependence of the beam angles of the beam bundles is stored in a control and evaluation unit, which, in addition to the temperature of the facet lens transmitted by the temperature sensors, are taken into account by the control and evaluation unit when evaluating the recordings of the image recording unit. The device and method are described in the context of facet lenses that are used to determine the topography of an eye. However, in principle, they are usable wherever an existing temperature dependence, in particular of optical components, should be compensated for.

Arrangement and method for compensating for the temperature dependence of a facet lens for determining the topography of an eye

A device for determining biometric variables of the eye, as are incorporated in the calculation of intraocular lenses including a multi-point keratometer and an OCT arrangement. The keratometer measurement points are illuminated telecentrically and detected telecentrically and the OCT arrangement is designed as a laterally scanning swept-source system with a detection region detecting the whole eye over the whole axial length thereof. Illumination points are arranged in three rings concentrically around an instrument axis; and the three rings include a first ring, a second ring and a third ring and the illumination points on the first ring and the third ring are rotated in relation to the illumination points on the second ring such that each of the illumination points on the first ring is on a common radial with one of the illumination points on the third ring and each of the illumination points on the second ring is not on the common radial.

Device for reliably determining biometric measurement variables of the whole eye

A method for capturing biometric measurement data of a patient's eye, in which the fixation is monitored during the entire biometric measurement. Information in respect of the fixation is extracted, depending on the different recording modes, from already available or additionally captured recordings and/or data. Central retinal OCT scans with absolute fixation information and frontal images with relative fixation information with or without at least partial diffuse lighting are used. On the basis of this extracted fixation information, the subsequent evaluation only uses the captured biometric measurement data captured just before, at the same time as or just after frontal images with the correct fixation. The method can also be applied to different measurement tasks, in which use is made of different measurement modes and in which the alignment of the measurement object is important for the measurement results.

Method for the continuous control of the fixation of a patient's eye during the detection of biometric measurement data of the patient's eye

A device for determining biometric variables of the eye, as are incorporated in the calculation of intraocular lenses including a multi-point keratometer and an OCT arrangement. The keratometer measurement points are illuminated telecentrically and detected telecentrically and the OCT arrangement is designed as a laterally scanning swept-source system with a detection region detecting the whole eye over the whole axial length thereof. The multi-point keratometer ensures that a sufficient number of keratometer points are available for measuring the corneal surface. By contrast, telecentricity ensures that the positioning inadequacies of the measuring instrument in relation to the eye to be measured do not lead to a local mismatch of the reflection points. The swept-source OCT scan detects the whole eye over the length thereof so that both anterior chamber structures and retina structures can be detected and a consistent whole eye image can be realized.

Knowledge of the anatomical, post-operative position and orientation influences not only the selection of the IOL to be implanted but also the result of the refractive operation on the eye. In the method for selecting an IOL to be implanted into an eye on the basis of the prediction of the anatomical, post-operative position (ALP) and orientation thereof, based on pre-operative measuring values such as, for example, anterior chamber depth (VKT), lens thickness (LD) and axial eye length (AL), the invention additionally or exclusively uses the curvature(s) of the eye lens or measuring values derived therefrom. The proposed method is used to predict the anatomical, post-operative position (ALP) and orientation of an intraocular lens (IOL) to be implanted into an eye.

Method for selecting an IOL on the basis of the prediction of the anatomical, post-operative position and orientation thereof

A method for classifying a cataract of an eye to determine parameters for pre-setting phaco-treatment instruments. OCT-based measurements are realized. The OCT-based scans are analysed using imaging technology and the local distribution of the cataract is determined. The cataract is classified on the basis of comparison values and the local distribution and classification of the cataract are used to identify parameters for pre-setting phaco-treatment instruments. Even though the proposed method for classifying the cataract of an eye is provided for determining parameters for pre-setting phaco-treatment instruments, it should equally also be used for determining parameters for pre-setting treatment instruments based on fs-lasers.

Method for classifying the cataract of an eye

A method for determining the topography of the cornea of an eye on the basis of an optical, contactless data capture. In the method for determining the topography of the cornea of an eye, which is based on a deflectometric method, the deflectometric measurements are carried out with the aid of a keratometric method by virtue of additional OCT-based scans being made at the keratometric measurement points, wherein the two measurement systems are registered to one another and both the keratometric and the OCT-based measurement values are recorded and used for mutual calibration to determine and output the topographic data. The proposed method serves to determine the topography of the cornea of an eye. It is helpful to ascertain the topography in order to be able to draw conclusions about possible pathological changes. Moreover, the exact measurement of the corneal topography is of great importance for correcting refractive errors.

Method for determining the topography of the cornea of an eye

A method for measuring the geometric parameters of the eye. These measurements, known by the term biometrics, are particularly significant for the calculation of intraocular lenses after previous refractive cornea surgery. OCT images and other images are recorded simultaneously, the intensity of the reflected light generated during the OCT image recordings being lower by a factor of 2, by a factor of 10 or by a factor of 100, than the intensity of the illumination light of the other image recordings. The solution provides a method for producing other image recordings, in addition to OCT recordings, in the form of representations of the sclera or of the fundus, or keratometric, topographic or biometric measurements, or even short image sequences, for instance, while aligning the device with the eye.

Method for producing OCT images and other images of an eye including reducing the intensity of reflected light

A method for selecting an intraocular lens (IOL), to optimize the results of refractive procedures on the eye. According to the invention, the method for selecting the IOL includes: a) determining the required biometrical parameters of the eye; b) using the parameters for a corresponding eye model; c) evaluating, using ray tracing, the data of an IOL to be implanted; d) selecting, on the basis of said data, an IOL to be implanted; and e) repeating the method steps c) and d) for further suitable IOLs. To optimize the method, different measuring methods are used to determine the biometrical parameters, a corresponding patient-specific eye model is identified, and, when selecting the IOL, additional retinal image metrics are taken into consideration alongside the determined data. The method according to the invention permits the optimized selection of a spherical, aspheric, toric or multifocal IOL for implantation.

Method for optimizing the selection of the IOL to be implanted in an eye

A method for determining the axial length of an eye by optical coherence tomography (OCT), in which the alignment of the measuring instrument to the eye is monitored to enable reliable determination of the axial length of the eye. B-scans are carried out following alignment from which scans of the retinal tissue structures are detected to determine the axial lengths, which are then used in the detection of the fovea in order to monitor alignment. The axial lengths determined from the B-scans are then confirmed or corrected and output depending, on the determined position of the fovea or the lateral distance thereof from the optical axis of the measuring instrument. The method is particularly suitable for OCT methods in which the axial length is determined on the basis of an A-scan along the axial dimension of the eye.

Method for the reliable determination of the axial length of an eye

For the model-based determination of the biometry of eyes, the eye is illuminated by a light source via a scanning unit, the focus of the measuring light beam in the eye is moved or shifted laterally and/or axially via an adjusting device and the light fractions back-scattered by the boundary surfaces and from the tissue of the eye via an interferometer are detected by a sensor and relayed to a control and evaluation unit by which a parametric eye model which describes at least two boundary surfaces present in the eye is adapted to the scan or scans. The invention relates to the field of ophthalmology and serves in particular for the optical determination of the biometry of eyes by application of two-dimensional optical coherence tomography images. However, the method is not limited to the use of coherence tomography nor to the utilization of optical measurements.

Method for the model-based determination of the biometry of eyes

A method for determining the total refractive power of the cornea is based on a combination of keratometric or topographic measurements using the measured values obtained from depth scans or sectional images. The radius (Ra) of the front side of the cornea is ascertained keratometrically or topographically, the radius (Rp) of the rear side of the cornea is determined from depth scans or sectional images, and the refractive power (Ka) of the front side of the cornea, the refractive power (Kp) of the rear side of the cornea, and the total refractive power (K) of the cornea are determined. The method is used to determine the total refractive power of the cornea of an eye and is not just applicable to eyes with normal vision but in particular also to astigmatic eyes.

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Jena, Germany

Ferid Bajramovic