Methods and apparatus for detecting a presence and severity of a cataract in ambient lighting

Patent metadata

Field	Value
Publication number	US-11969212-B2
Application number	US-202318175925-A
Country	US
Kind code	B2
Filing date	Feb 28, 2023
Priority date	Dec 27, 2019
Publication date	Apr 30, 2024
Grant date	Apr 30, 2024

Abstract

Disclosed herein are methods and apparatus for making a determination about a cataract in an eye in ambient lighting conditions.

First claim

What is claimed:

1. A method of detecting cataracts in an eye of a subject, the method comprising:
capturing, by an image capture device, an image of the eye of the subject, wherein the image is captured using only ambient lighting conditions;
determining, by a computing device in communication with the image capture device, ocular opacification and brunescence in the eye of the subject based on the image; and
determining, by the computing device, a presence and severity of a cataract in the eye of the subject based on the determined ocular opacification and brunescence.

2. The method of claim 1 , wherein ocular opacification and brunescence are determined based on reflected ambient light, and wherein determining ocular opacification and brunescence in the eye of the subject comprises:
determining, by the computing device, an overall intensity of light from a plurality of pixels located within the portion of the pupil of the eye of the subject captured in the image;
determining, by the computing device, a first intensity of a first color from the plurality of pixels located within the portion of the pupil of the eye of the subject captured in the image;
determining, by the computing device, a second intensity of a second color from the plurality of pixels located within the portion of the pupil of the eye of the subject captured in the image; and
comparing, by the computing device, a relative intensity of the first color and a relative intensity of the second color, wherein ocular opacification and brunescence are determined based on the comparison and the overall intensity.

3. The method of claim 2 , further comprising:
determining, by the computing device, a color temperature of the ambient lighting, wherein at least one of the overall intensity of light, the first intensity of the first color, or the second intensity of the second color is adjusted by the computing device based on the determined color temperature of the ambient lighting.

4. The method of claim 1 , wherein the determination of ocular opacification and brunescence in the eye of the subject is based on a brightness and one or more colors of reflected ambient light.

5. The method of claim 4 , wherein the brightness is adjusted by the computing device based on a determined color temperature of the ambient lighting.

6. The method of claim 1 , wherein the ocular opacification and the brunescence are graded according to clinical severity and effect of the cataract on visual acuity.

7. The method of claim 1 , further comprising:
managing non-relevant reflections in the image of the eye of the subject by at least one of applying a polarizing filter over a lens of the image capture device, blocking external light sources, or providing a surface that absorbs light to prevent the non-relevant reflections.

8. The method of claim 1 , wherein ocular opacification and brunescence are determined based on a relative intensity and noise of RGB pixel values in the image after correcting for a color temperature of the ambient lighting.

9. The method of claim 1 , wherein the determination of ocular opacification and brunescence is made based on an unmodified version of the image of the eye of the subject.

10. The method of claim 1 , wherein the cataract is a nuclear cataract.

11. The method of claim 1 , wherein the image capture device and the computing device are part of a smartphone.

12. A device for detecting cataracts in an eye of a subject, the device comprising:
an image capture unit;
a processor; and
memory having instructions stored thereon that, when executed by the processor, cause the device to:
capture, by the image capture unit, an image of the eye of the subject, wherein the image is captured using only ambient lighting conditions;
determine ocular opacification and brunescence in the eye of the subject based on the image; and
determine a presence and severity of a cataract in the eye of the subject based on the determined ocular opacification and brunescence.

13. The device of claim 12 , wherein ocular opacification and brunescence are determined based on reflected ambient light, and wherein to determine ocular opacification and brunescence in the eye of the subject, the instructions further cause the device to:
determine an overall intensity of light from a plurality of pixels located within the portion of the pupil of the eye of the subject captured in the image;
determine a first intensity of a first color from the plurality of pixels located within the portion of the pupil of the eye of the subject captured in the image;
determine a second intensity of a second color from the plurality of pixels located within the portion of the pupil of the eye of the subject captured in the image; and
compare a relative intensity of the first color and a relative intensity of the second color, wherein ocular opacification and brunescence are determined based on the comparison and the overall intensity.

14. The device of claim 13 , wherein the determination of ocular opacification and brunescence in the eye of the subject is based on a brightness and one or more colors of reflected ambient light, and wherein the brightness is adjusted based on a determined color temperature of the ambient lighting.

15. The device of claim 12 , wherein the ocular opacification and the brunescence are graded according to clinical severity and effect of the cataract on visual acuity.

16. The device of claim 12 , wherein, in conjunction with capturing the image of the eye of the subject, non-relevant reflections are managed by at least one of applying a polarizing filter over a lens of the image capture device, blocking external light sources, or providing a surface that absorbs light to prevent the non-relevant reflections.

17. The device of claim 12 , wherein ocular opacification and the brunescence are determined based on a relative intensity and noise of RGB pixel values in the image after correcting for a color temperature of the ambient lighting.

18. The device of claim 12 , wherein the determination of ocular opacification and the brunescence is made based on an unmodified version of the image of the eye of the subject.

19. The device of claim 12 , wherein the cataract is a nuclear cataract.

20. The device of claim 12 , wherein the device is a smartphone.

Assignees

• Ohio State Innovation Foundation

Inventors

• Bailey Melissa
• Bosworth Charles

Classifications

• A61B3/1176 Primary

  for determining lens opacity, e.g. cataract · CPC title

• A61B3/0025

  characterised by electronic signal processing, e.g. eye models · CPC title

• G06T7/0016

  involving temporal comparison · CPC title

• G06T7/90

  Determination of colour characteristics · CPC title

• G06T2207/30041

  Eye; Retina; Ophthalmic · CPC title