Model eye producing a speckle pattern having a reduced bright-to-dark ratio for use with optical measurement system for cataract diagnostics

Patent metadata

Field	Value
Publication number	US-9468369-B2
Application number	US-201414559667-A
Country	US
Kind code	B2
Filing date	Dec 3, 2014
Priority date	Jan 21, 2011
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

A system includes a model eye and an optical measurement instrument, which includes: a corneal topography subsystem; a wavefront sensor subsystem; and an eye structure imaging subsystem. The subsystems may have a common fixation axis, and be operatively coupled to each other via a controller. The optical measurement instrument may perform measurements of the model eye to verify correct operation of the optical measurement instrument for measuring one or more characteristics of a subject's eye. The model eye may include an optically transmissive structure having a front curved surface and an opposite rear planar surface, and a material structure provided at the rear planar surface of the optically transmissive structure and having a characteristic to cause a speckle pattern of a portion of a coherent light beam that is directed back out the front curved surface of the optically transmissive structure to have a bright-to-dark ratio of less than 2:1.

First claim

We claim:

1. A method, comprising:
providing a model eye comprising an optically transmissive structure having a front curved surface and an opposite rear planar surface, and a material structure provided at the rear planar surface of the optically transmissive structure having a characteristic to cause a speckle pattern of a portion of a coherent light beam that is directed back out through the front curved surface of the optically transmissive structure to have a bright-to-dark ratio of less than 2:1;
performing one or more measurements of the model eye to verify correct operation of an optical measurement instrument which includes:
a corneal topography subsystem,
a wavefront sensor subsystem, and
an eye structure imaging subsystem; and

employing the optical measurement instrument to measure a plurality of characteristics of a subject's eye, comprising ocular biometry information, anterior corneal surface information, posterior corneal surface information, anterior lens surface information, posterior lens surface information, lens tilt information and lens position information.

2. The method of claim 1 , wherein the eye structure imaging subsystem comprises an optical coherence tomography subsystem, and wherein performing one or more measurements of the model eye to verify correct operation of the optical measurement instrument includes:
performing an optical coherence tomography measurement, with the optical coherence tomography subsystem, to measure a thickness of the material structure provided at the rear planar surface of the optically transmissive structure of the model eye;
comparing the measured thickness to a known thickness of the material structure provided at the rear planar surface of the optically transmissive structure of the model eye; and
when the measured thickness does not agree with the known thickness within a particular tolerance, determining that the optical measurement instrument is not operating properly within specifications.

3. The method of claim 1 , wherein the material structure comprises a fabric-reinforced polyethylene pressure-sensitive tape adhered to the rear planar surface of the optically transmissive structure by an adhesive.

4. The method of claim 1 , wherein the material structure comprises at least two layers of optically transmissive adhesive tape with a material having a plurality of light scattering particles disposed between the at least two layers of optically transmissive adhesive tape.

5. The method of claim 1 , wherein the material structure comprises a plurality of layers of optically transmissive adhesive tape with a plurality of pencil marks on each successive layer of the optically transmissive adhesive tape.

6. The method of claim 1 , wherein the material structure comprises a layer of optically transmissive paint with light scattering particles embedded within.

7. The method of claim 1 , wherein the material structure comprises a caulking material with a gauze material applied thereto.

8. The method of claim 1 , further comprising:
determining a desired postoperative condition of the subject's eye;
empirically calculating a post-operative condition of the eye based at least partially on the measured eye characteristics; and
predictively estimating, in accordance with an output of said empirically calculating and the eye characteristics, at least one parameter of an intraocular lens for implantation into the subject's eye to obtain the desired postoperative condition.

9. The method of claim 1 , wherein the ocular biometry information comprises a plurality of central corneal thicknesses (CCT), an anterior chamber depth (ACT), a pupil diameter (PD), a white to white distance (WTW), a lens thickness (LT), an axial length (AL) and a retinal layer thickness.

10. The method of claim 1 , further comprising:
accessing a plurality of Intraocular Lens (IOL) models stored in a memory accessible by the optical measurement instrument, each of the IOL models having associated with it a plurality of predetermined parameters selected from the group consisting of dioptic power, refractive index, asphericity, toricity, haptic angulation and lens filter; and
for each of the IOL models:
(1) modeling the subject's eye with an intraocular lens corresponding to the IOL model and the measured characteristics of the subject's eye;
(2) simulating the subject's eye based on the plurality of IOL predetermined parameters and the predicted IOL position;
(3) performing one of a ray tracing and a power calculation based on said model of the subject's eye; and
(4) selecting an IOL for the subject's eye from the plurality of IOL models corresponding to the optimized IOL based on a predetermined criteria.

11. The method of claim 1 , wherein the material structure provided at the rear planar surface of the optically transmissive structure of the model eye has a plurality of layers, wherein the eye structure imaging subsystem comprises an optical coherence tomography subsystem, and wherein performing one or more measurements of the model eye to verify correct operation of the optical measurement instrument includes:
performing an optical coherence tomography measurement, with the optical coherence tomography subsystem, to measure thicknesses of at least two of the layers of the material structure provided at the rear planar surface of the optically transmissive structure of the model eye;
comparing the measured thicknesses to known thicknesses of the at least two layers of the material structure provided at the rear planar surface of the optically transmissive structure of the model eye; and
when the measured thicknesses for the at least two layers do not agree with the known thicknesses of the at least two layers within a particular tolerance, determining that the optical measurement instrument is not operating properly within specifications.

12. A system, comprising:
a model eye, comprising:
an optically transmissive structure having a front curved surface and an opposite rear planar surface, and
a material structure provided at the rear planar surface of the optically transmissive structure and having a characteristic to cause a speckle pattern of a portion of a coherent light beam that is directed back out through the front curved surface of the optically transmissive structure to have a bright-to-dark ratio of less than 2:1; and

an optical measurement instrument which includes:
a corneal topography subsystem,
a wavefront sensor subsystem, and
an eye structure imaging subsystem,

wherein the subsystems have a common fixation axis, and each subsystem is operatively coupled to the others via a controller, and
wherein the optical measurement instrument is configured to perform one or more measurements of the model eye to verify correct operation of the optical measurement instrument for measuring one or more characteristics of a subject's eye.

13. The system of claim 12 , wherein the material structure comprises a fabric-reinforced polyethylene pressure-sensitive tape adhered to the rear planar surface of the optically transmissive structure by an adhesive.

14. The system of claim 12 , wherein the material structure comprises at least two layers of optically transmissive adhesive tape with a material having a plurality of light scattering particles disposed between the at least two layers of optically transmissive adhesive tape.

15. The system of claim 12 , wherein the material structure comprises a plurality of layers of optically transmissive adhesive tape with a plurality of pencil marks on each successive layer of the optically transmissive adhesive tape.

Assignees

• Amo Wavefront Sciences Llc
• Amo Wavefront Sciences Llc

Inventors

• Copland Richard J
• Neal Daniel R
• Raymond Thomas D
• Xiong Wei
• Pulaski Paul D
• Farrer Stephen W
• Canovas Vidal Carmen
• Hamrick Daniel R

Classifications

• A61F2/142

  Cornea, e.g. artificial corneae, keratoprostheses or corneal implants for repair of defective corneal tissue · CPC title

• A61F2/14

  Eye parts, e.g. lenses or corneal implants; Artificial eyes · CPC title

• A61B3/102

  for optical coherence tomography [OCT] · CPC title

• A61F2/16

  Intraocular lenses · CPC title

• A61B3/107

  for determining the shape or measuring the curvature of the cornea · CPC title