SYSTEMS AND METHODS FOR NONINVASIVE ANALYSIS OF RETINAL HEALTH AND FUNCTION

• US 20130128227A1
• Filed: 11/21/2012
• Published: 05/23/2013
• Est. Priority Date: 11/22/2011
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Cui, Xiquan, Fraser, Scott E.
• Granted Patent: US 9,010,935 B2
• Time in Patent Office: Days
• US Class Current: 351/211
• CPC Class Codes: A61B 3/10 Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
• CPC Class Codes: A61B 3/12 for looking at the eye fundus, e.g. ophthalmoscopes A61B3/13 takes precedence

Abstract

A method for noninvasive analysis of a retina includes exposing the retina to one or more first sets of at least three illumination light signals. The at least three illumination light signals each have a different wavelength. The method also includes optically collecting a reflected light signal for each of the at least three illumination light signals of the one or more first sets. Each of the reflected light signals is a portion of the respective illumination light signal reflected by the retina. The method further includes detecting the reflected light signals of the one or more first sets as a function of intensity. The method still further includes determining a first opsin density using the detected intensity of each of the reflected light signals of the one or more first sets.

Claims

1. A method for noninvasive analysis of a retina, comprising:

exposing the retina to one or more first sets of at least three illumination light signals generated by one or more light sources, the at least three illumination light signals each having a different wavelength;

optically collecting a reflected light signal for each of the at least three illumination light signals of the one or more first sets, each of the reflected light signals being a portion of the respective illumination light signal reflected by the retina;

detecting, via a light detector, the reflected light signals of the one or more first sets as a function of intensity;

determining, via one or more processors, a first opsin density using the detected intensity of each of the reflected light signals of the one or more first sets.

2. The method of claim 1, further comprising, prior to the exposing the retina to the one or more first sets of at least three illumination light signals, exposing the retina to dark conditions for a period of time to cause full dark-adaption.

3. The method of claim 1, further comprising exposing the retina to a photobleaching light signal, the photobleaching light signal being configured to photobleach the retina.

4. The method of claim 3, further comprising:

after the exposing the retina to the photobleaching light signal, exposing the retina to one or more second sets of the at least three illumination light signals;

optically collecting a reflected light signal for each of the at least three illumination light signals of the one or more second sets;

detecting, via the light sensor, the reflected light signals of the one or more second sets as a function of intensity; and

determining, via at least one of the one or more processors, a second opsin density using the detected intensity of each of the reflected light signals of the one or more second sets.

5. The method of claim 4, further comprising determining a regeneration speed of the opsin based on at least the second opsin density.

6. The method of claim 5, wherein the regeneration speed is determined by a calculation having the general form of the following equation:

7. The method of claim 5, wherein the determining a second opsin density comprises determining an initial and a subsequent opsin densities and the regeneration speed is determined by a calculation having the general form of the following equation:

8. The method of claim 5, wherein the regeneration speed is determined for a plurality of spatial points on the retina and the method further comprises mapping the determined regeneration speeds to the spatial points on the retina to generate an image of the retina including indications of the regeneration speeds relative to the plurality of spatial points.

9. The method of claim 1, wherein the first opsin density is determined for a plurality of spatial points on the retina and the method further comprises generating an image of the retina mapping the first opsin densities to the plurality of spatial points.

10. The method of claim 9, wherein the first opsin density is determined prior to exposing the retina to a photobleaching light source.

11. The method of claim 1, wherein the opsin is rhodopsin.

12. The method of claim 11, wherein the first opsin density is determined from a plurality of equations having the general form:

13. The method of claim 1, wherein the exposing and the optically collecting are via a fundus camera.

14. The method of claim 1, wherein the at least three illumination light signals includes a first light signal having a wavelength of approximately 470 nm, a second light signal having a wavelength of approximately 500 nm, and a third light signal having a wavelength of approximately 660 nm.

15. The method of claim 14, wherein the intensity of the first light signal, the second light signal, and the third light signal is less than approximately 30 μ

W.

16. The method of claim 14, wherein the exposing the retina to the at least three illumination light sources includes exposing the retina to the first light signal, the second light signal, and the third light signal for approximately 30 milliseconds each.

17. A system for noninvasive analysis of a retina, comprising:

one or more light sources configured to generate at least three illumination light signals, each of the at least three illumination light signals having a different wavelength;

one or more optical components configured to direct the at least three illumination light signals from the one or more light sources to one or more spatial points on the retina;

an light detector, the one or more optical components further being configured to direct a plurality of reflected light signals from the retina to the light detector, the light detector being configured to receive the reflected light signals as a function of intensity;

one or more processors; and

one or more memory devices storing instructions that, when executed by the one or more processors, cause the system to;

generate, via the one or more light sources, a first set of the at least three illumination light signals,

detect, via the light detector, the reflected light signals in response to the generation of the first set of the at least three illumination signals, and

determine a first opsin density using the detected intensity of the reflected light signals.

19. The system of claim 17, further comprising a photobleaching light source configured to generate a photobleaching light signal having a wavelength, an intensity, and a duration for photobleaching the retina.

20. The system of claim 19, wherein the instructions further cause the system to:

after the generation of the photobleaching light signal, generate, via the one or more light sources, a second set of the at least three illumination light signals,

detect, via the light sensor, the reflected light signals of the one or more second sets as a function of intensity; and

determine a second opsin density using the detected intensity of each of the reflected light signals of the one or more second sets.

21. The system of claim 20, wherein the instructions further cause the system to determine the regeneration speed of the opsin based on the determined second opsin density.

22. The system of claim 21, wherein the instructions further cause the system to map the regeneration speed of the opsin onto an image of the retina.

23. The system of claim 17, wherein the instructions further cause the system to map the first opsin density onto an image of the retina.

24. The system of claim 17, wherein the instructions are configured to cause the one or more processors to determine the first opsin density from a plurality of equations having the general form:

25. The system of claim 17, wherein the instructions are configured to synchronize generation of the at least three illumination light signals, and a plurality of corresponding exposure times for the light detector.

26. The system of claim 17, further comprising a galvanometer configured to direct the at least three illumination signals to the retina according to a raster scanning scheme.

27. The system of claim 17, further comprising an annulus mirror configured to direct the at least three illumination light signals from the one or more light sources to the retina, the annulus mirror including an aperture configured to allow the reflected light signals to pass from the retina to the light detector.