Method and apparatus for early detection and classification of retinal pathologies

• US 6,735,331 B1
• Filed: 09/05/2000
• Issued: 05/11/2004
• Est. Priority Date: 09/05/2000
• Status: Expired due to Fees

• Current Assignee: Talga Technologies Limited
• Original Assignee: Talga Technologies Limited
• Inventors: Karpol, Avner, Binnun, Emanuel
• Primary Examiner(s): Johnson, Timothy M.
• Assistant Examiner(s): AZARIAN, SEYED H
• Application Number:
  US09/655,371
• Time in Patent Office: 1,344 Days
• Field of Search: 382/128, 382/127, 382/129, 382/130, 382/133, 382/134, 382/132, 382/154, 514/913, 514/914, 514/206, 514/221, 514/68, 514/78, 514/912, 514/63, 424/78.04, 424/93.21, 356/456, 356/632, 351/221, 351/206, 351/402, 600/408, 600/407, 600/476, 430/30
• US Class Current: 382/133
• CPC Class Codes: A61B 3/12 for looking at the eye fundus, e.g. ophthalmoscopes A61B3/13 takes precedence
• CPC Class Codes: A61B 3/1225 using coherent radiation

Abstract

A method and apparatus for early detection and classification of retinal pathologies, especially glaucoma and macular edema. The method comprises; (a) illuminating predetermined locations on the retina; (b) receiving light returning from predetermined locations; (c) generating a series of primary graphs corresponding to the light intensity with respect to retinal depth of predetermined locations on the retina; (d) separating the component curves of said graphs; (e) analyzing said component curves to produce data including data corresponding to the front slope and/or the back slope, and/or the area of at least one of said component curves; (f) comparing said data to analogous pre-specified data.

Claims

1. A method of detecting and classifying retinal pathologies, including glaucoma and diabetic macular edema, said method comprising:

(a) illuminating a sequence of predetermined locations on a retina;

(b) receiving light returning from said predetermined locations;

(c) generating a series of primary graphs each representing the intensity of the returning light as a function of the retinal depth at one of said predetermined locations;

(d) separating each of said primary graphs into a first component curve corresponding to the light returning substantially from the Nerve Fiber Layer of the retina and a second component curve corresponding to the light returning substantially from the Retinal Pigment Epithelium of the retina;

(e) analyzing at least one of said component curves to obtain data including, but not limited to, data corresponding to the front slope and/or back slope and/or area of said at least one of said component curves; and

(f) comparing the data to analogous pre-specified data.

2. A method according to claim 1, further comprising determining the retinal thickness at each of said predetermined locations.

3. A method according to claim 1, wherein the data is arranged in a matrix for enabling comparison with the pre-specified data arranged in an analogous format.

4. A method according to claim 1, further comprising generating at least one three-dimensional map.

5. A method according to claim 1, further comprising generating at least one three-dimensional map corresponding to the relative amount of cells in the Nerve Fiber Layer of the retina over the sequence of said predetermined locations.

6. A method according to claim 1, wherein the data corresponds to the area of the first component curve that corresponds to the Nerve Fiber Layer of the retina.

7. A method according to claim 1, wherein the data corresponds to the ratio of the area of the first component curve corresponds to the Nerve Fiber Layer to the area of the second component curve corresponding to the Retinal Pigment Epithelium.

8. A method according to claim 1, wherein the data corresponds to the ratio of the area of the first component curve corresponding to the Nerve Fiber Layer to the area of the respective primary graph.

9. A method according to claim 1, wherein the data corresponds to differences between the Line Spread Function of the first component curve corresponding to the Nerve Fiber Layer and the Line Spread Function of the second component curve corresponding to the Retinal Pigment Epithelium.

10. A method according to claim 9, wherein the comparison between the Line Spread Functions includes comparing the slope of a rear, descending portion of the second component curve corresponding to the Retinal pigment epithelium with the slope of a front, ascending, portion of the first component curve corresponding to the Nerve Fiber Layer.

11. A method according to claim 1, wherein the data corresponds to the slope of a rear, descending portion of the second component curve corresponding to the Retinal pigment epithelium.

12. A method according to claim 1, wherein the pre-specified data is obtained from normal retinas.

13. A method according to claim 1, wherein the pre-specified data is obtained from an earlier examination of the retina being examined.

14. A method according to claim 1, wherein the regions of the retina are illuminated successively according to a predetermined illumination sequence useful for the detection of a specific retinal region.

15. An apparatus for mapping the inner structure of a retina and for use in early detection of retinal pathologies, including glaucoma and diabetic macular edema, said apparatus comprising:

illuminating means for illuminating a sequence of predetermined locations on the retina and for receiving light returning from said predetermined locations; and

computing means for producing a series of primary graphs each representing the intensity of the returning light as a function of the retinal depth at one of said predetermined locations, for separating each of said primary graphs into a first component curve corresponding to the light returning substantially from the Nerve Fiber Layer of the retina and a second component curve corresponding to the light returning substantially from the Retinal Pigment Epithelium of the retina, for analyzing the component curves to obtain data corresponding to at least one of the front slope, the back slope and the area of at least one of said primary curves and component curves, and for comparing said data to analogous pre-specified data to quantify changes in the retina.

16. A method of detecting and classifying retinal pathologies, including glaucoma and diabetic macular edema, said method comprising:

(a) illuminating at least a region of a retina;

(b) receiving, light returning from said region;

(c) representing the intensity of a first component of the returning light, which first component returns substantially from the Nerve Fiber Layer in said region of the retina, as a first function of the retinal depth in said region;

(d) representing the intensity of a second component of the returning light, which second component returns substantially from the Retinal Pigment Epithelium in said region of the retina, as a second function of the retinal depth in said region;

(e) analyzing at least one of said first and second functions to obtain data relating to said at least one of said functions; and

(f) comparing the obtained data to pre-specified data.