System and Method for Illumination and Fixation with Ophthalmic Diagnostic Instruments

• US 20080284979A1
• Filed: 05/17/2007
• Published: 11/20/2008
• Est. Priority Date: 05/17/2007
• Status: Active Grant

• Current Assignee: AMO Development LLC (Johnson & Johnson)
• Original Assignee: VISX Incorporated
• Inventors: Yee, Kingman, Somani, Seema
• Granted Patent: US 8,016,420 B2
• Time in Patent Office: Days
• US Class Current: 351/209
• CPC Class Codes: A61B 3/0091 Fixation targets for viewing direction
• CPC Class Codes: A61B 3/103 for determining refraction, e.g. refractometers, skiascopes

Abstract

An eye measurement system may include a target that moves transverse to an optical path from the target to eye, so as to relax accommodation of the lens of the eye. The target may move transverse to the optical path on a display. The patient may be fogged while the target moves transverse to the optical path, and the target may become smaller such that the patient perceives the target to be moving away from the patient. A pupil camera may measure eye position that can be correlated with the position of the target on the display to determine that the patient has maintained fixation on the moving target. A visible measurement light beam may be pulsed subsequent to and/or during motion of the target that relaxes accommodation of the eye so as to avoid visual interference of the measurement light beam with the target on the display.

Claims

1. An optical device to diagnose an eye of a patient, the device comprising:

a display with a target visible to a patient;

an optical system to project the target along an optical path from the display to the patient, wherein the display is adapted to move the target transverse to the optical path; and

a sensor to measure optical aberrations of the eye in response to movement of the target transverse to the optical path.

2. The optical device of claim 1 wherein transverse movement of the target comprises at least one of a translation or a rotation of the target.

3. The optical device of claim 1 wherein the display comprises a microdisplay with pixel elements.

4. The optical device of claim 1 wherein the display comprises a computer addressable display with pixel elements that move the target across the display.

5. The optical device of claim 1 wherein the display comprises at least one of an organic light emitting diode microdisplay, a liquid crystal microdisplay, a liquid crystal on silicon microdisplay, or a MEMS microdisplay.

6. The optical device of claim 1 further comprising a processor configured to move the target transverse to the optical axis and measure the optical properties of the eye.

7. The optical device of claim 6 wherein the processor is configured to rotate virtually a target object on the display.

8. The optical device of claim 6 wherein the processor is configured to decrease a size of the image while the optical system fogs the target.

9. The optical device of claim 6 wherein the processor is configured to correlate a position of the target transverse to the optical path with a position of the eye.

10. The optical device of claim 6 wherein the processor is configured to adjust a vergence of the target with the optical system and measure a range of accommodation of the eye in response to the vergence of the target.

11. The optical device of claim 1 further wherein the display comprises a stationary scene while the target moves transverse to the optical axis.

12. The optical device of claim 1 further comprising a sensor to measure a position of the eye as the target moves transverse to the optical axis.

13. A method of diagnosing an eye with a sensor, the method comprising:

presenting a target on a display to a patient;

projecting the target along a path from the display to the patient;

moving the target transverse to the optical path to relax an accommodation of the eye; and

measuring optical aberrations the eye with the sensor.

14. The method of claim 13 wherein the target is moved transverse to the optical path with at least one of a translation or a rotation.

15. The method of claim 13 wherein the display comprises a stationary scene while the target moves transverse to the optical path.

16. An optical device to diagnose an eye of a patient, the device comprising:

a display with a target visible to a patient;

an optical system to project the target display along an optical path from the display to the patient;

a sensor to measure optical aberrations of the eye; and

a pulsed measurement light source coupled to the measurement sensor and visible to the patient, wherein the pulsed light source is pulsed while the target is configured to relax an accommodation of the eye of the patient.

17. The diagnostic device of claim 16, wherein the pulsed measurement light source is synchronized with the target.

18. The diagnostic device of claim 16, wherein the optical system is adapted to fog the target to relax the accommodation of the eye.

19. The diagnostic device of claim 16, wherein the pulsed light source is synchronized with the sensor.

20. The diagnostic device of claim 16, wherein the pulsed light source is synchronized with a frame transfer rate to a processor.

21. The diagnostic device of claim 16, wherein the light source comprises at least one of a laser, a super luminescent diode or a light emitting diode.

22. The diagnostic device of claim 16, wherein the sensor comprises at least one of a Shack-Hartmann wavefront sensor, a Tscherning aberrometer, or a spatially resolved refractometer.

23. A method of diagnosing an eye of a patient with a sensor, the method comprising:

presenting a target on a display with the target visible to the patient;

pulsing a light source visible to the patient to measure aberrations of the eye while the target is configured to relax an accommodation of the eye of the patient.

24. The method of claim 23 wherein the target moves transverse to an optical path from the target to the patient.

25. The method of claim 24 wherein the light source is pulsed in response to a common timing signal and wherein the target moves transverse to the optical path in response to the common timing signal.

26. An optical device to diagnose aberrations of an eye of a patient, the device comprising:

an aberration sensor to measure the optical aberrations of the eye; and

a pulsed measurement light source synchronized with the measurement sensor, wherein the pulsed light source is pulsed for a short duration to avoid visual interference with a fixation target.

27. The diagnostic device of claim 26, wherein the pulsed measurement light source is adapted to pulse a few times with each pulse synchronized to a separate frame of the sensor.

28. The diagnostic device of claim 27 wherein a duration of each pulse of the measurement light source corresponds to no more than about 30% of a duration of the separate frame of the sensor.

29. The diagnostic device of claim 26, wherein the short pulse comprises a short duration no more than about 100 ms and the long pulse threshold corresponds to a long duration of at least about 500 ms.

30. The diagnostic device of claim 26, wherein the pulsed measurement light source comprises infrared light.