Methods for assessing a physiological state of a mammalian retina

• US 7,706,863 B2
• Filed: 08/26/2004
• Issued: 04/27/2010
• Est. Priority Date: 01/21/2004
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Seibel, Eric J., Palczewski, Krzysztof, Imanishi, Yoshikazu, Sires, Bryan S.
• Primary Examiner(s): Le; Long V
• Assistant Examiner(s): Weatherby; Ellsworth
• Application Number:
  US10/926,780
• Publication Number:
  US 20050159662A1
• Time in Patent Office: 2,070 Days
• Field of Search: 600/473, 600/317, 600/318, 351/200
• US Class Current: 600/473
• 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 3/1025 for confocal scanning
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence

Abstract

In one aspect the present invention provides methods for assessing a physiological state of a mammalian retina in vivo, the methods of this aspect of the invention each include the steps of: (a) irradiating a portion of a mammalian retina, in vivo, with light having a wavelength in the range of from 600 nm to 1000 nm at an intensity sufficient to stimulate two-photon-induced fluorescence in the retina; and (b) assessing a physiological state of the retina by analyzing the fluorescence.

Claims

1. A method for assessing a physiological state of a mammalian retina in vivo, the method comprising the steps of:

(a) irradiating a portion of a mammalian retina, in vivo, with short-pulse light from a laser having a wavelength in the range of from 600 nm to 1000 nm at an intensity sufficient to stimulate two-photon-induced fluorescence in the retina;

(b) detecting the two-photon-induced fluorescence from the retina using a photon detector to produce a pixel; and

(c) repeating steps (a) and (b) to collect a plurality of pixels,

(d) producing an image from the plurality of pixels, wherein the image visualizes at least one retinosome; and

(e) assessing the physiological state of the retina based on the at least one retinosome.

2. The method of claim 1 wherein assessing comprises measuring an increase in the fluorescence of the retinosome after the retina is irradiated with the light.

3. The method of claim 1 assessing comprises measuring an increase and a decrease in the fluorescence of the retinosome after the retina is irradiated with the light.

4. The method of claim 1 wherein assessing comprises measuring a decrease in the fluorescence of the retinosome after the retina is irradiated with the light.

5. The method of claim 1 wherein the retina is a human retina.

6. The method of claim 1 wherein the retina is a canine retina or a feline retina.

7. The method of claim 1 wherein the light used to irradiate the retina has a wavelength in the range of from 650 nm to 850 nm.

8. The method of claim 1 wherein the light used to irradiate the retina has a wavelength in the range of from 710 nm to 740 nm.

9. The method of claim 1 wherein the light used to irradiate the retina irradiates a fixed focal volume of the retina and the light at the fixed focal volume has an optical power of from 0.05 mW to 25 mW.

10. The method of claim 1 wherein the light used to irradiate the retina irradiates a fixed focal volume of the retina and the light at the fixed focal volume has an optical power of from 0.5 mW to 15 mW.

11. The method of claim 1 wherein the two-photon-induced fluorescence has a wavelength in the range of from 400 nm to 640 nm.

12. The method of claim 1 wherein the irradiated portion of the mammalian retina has an area of from 250 μ

m² to 500,000 μ

m².

13. The method of claim 1 wherein the retina is irradiated though the sclera.

14. The method of claim 13 wherein the two-photon-induced fluorescence that passes though the sclera is analyzed to determine the physiological state of the retina.

15. The method of claim 14 wherein a clearing agent is applied to the sclera before or during irradiating a portion of the retina.

16. The method of claim 15 wherein the clearing agent is selected from the group consisting of glucose, glycerol, propylene glycol, and dimethylsulfoxide.

17. The method of claim 13 wherein irradiating a portion of the retina comprises irradiating a portion of the sclera that is compressed.

18. The method of claim 13 further comprising, measuring the two-photon-induced fluorescence through the pupil.

19. The method of claim 13 wherein irradiating a portion of the retina comprises irradiating through a portion of the equatorial region of the sclera.

20. The method of claim 1 wherein irradiating a portion of the retina comprises irradiating through the pupil.

21. The method of claim 20 wherein the two-photon-induced fluorescence is measured through the pupil.

22. The method of claim 20 wherein the pupil is dilated.

23. The method of claim 1 wherein irradiating a portion of the retina comprises irradiating with a scanning laser opthalmoscope.

24. The method of claim 1 wherein a second harmonically generated light emitted by the sclera is detected, and the detected light is used to determine whether the light having a wavelength in the range of from 600 nm to 1000 nm is focused on the portion of the retina or on a portion of the sclera.

25. The method of claim 1 wherein irradiating a portion of the retina comprises irradiating with a laser with a repetition frequency in the range of from 76 MHz to 100 MHz.

26. The method of claim 1 wherein irradiating a portion of the retina comprises irradiating with light having a pulse length in the range of from 10 fs to 1000 fs.

27. The method of claim 1 wherein the physiological state of the retina is determined by measuring the total amount of two-photon-induced fluorescence emitted by a portion of the retina.

28. The method of claim 1 further comprising displaying the image on a monitor to visualize the retinosome in the retina for assessing a physiological state of the retina.