System and method for objective chromatic perimetry analysis using pupillometer
View Patent ↗The present invention relates to a system, device and a method for objective visual field testing and in particular, to such a system and method in which provides objective chromatic perimetry test or color vision test using a pupillometer.
1. A pupillometer comprising:
a processor;
at least one camera; and
a testing compartment provided in the form of a substantially hemispheric bowl; wherein
the substantially hemispheric bowl comprises a plurality of chromatic beam emitters arranged about a visual field forming a plurality of visual field testing points,
the chromatic beam emitters generate a plurality of chromatic stimuli about the visual field testing points,
the chromatic stimuli comprise a first chromatic beam stimulus and a second chromatic beam stimulus,
at least one of the first chromatic beam stimulus and the second chromatic beam stimulus employs a wavelength that stimulates ganglion cells,
the testing compartment further comprises a light adaptation emitter,
the inner surface further comprises a fixation point opposite a subject's line of sight,
the at least one camera records pupil contraction in response to the first and second chromatic beam stimuli,
the processor controls the chromatic beam emitters and the stimulus parameters of the chromatic beam emitters, and
the processor processes data associated with and generated by the first and second chromatic beam stimuli and the camera and is programmed to
generate quantitative pupillary light reflex (PLR) measurements of a PLR in response to chromatic beam stimuli presented at the plurality of visual field testing points,
determine ratios of the quantitative PLR measurements at the plurality of visual field testing points, wherein each of the ratios at each testing point represents a quantitative PLR measurement at the first chromatic beam stimulus relative to a quantitative PLR measurement at the second chromatic beam stimulus, and
determine the state of health of the eye utilizing the ratios, wherein (i) the first chromatic beam stimulus employs a shorter-wavelength chromatic beam, relative to the second chromatic beam stimulus, (ii) the second chromatic beam stimulus employs a longer-wavelength chromatic beam, relative to the first chromatic beam stimulus, and (iii) the wavelengths of the first chromatic beam stimulus and the second chromatic beam stimulus are selected from the visual spectrum spanning from about 390 nm to about 750 nm.
2. The pupillometer of claim 1 , further comprising a controllable shutter for controlling the size and/or shape of the generated stimulus.
3. The pupillometer of claim 2 , wherein the shutter size corresponds to a stimulus having a substantially circular formation with a diameter from about 0.8 cm to about 2 cm.
4. The pupillometer of claim 1 , wherein the at least one camera comprises two or more cameras for recording a PLR of at least one tested eye.
5. The pupillometer of claim 4 , wherein the PLR is recorded for each eye using the two or more cameras.
6. The pupillometer of claim 1 , wherein the ratios characterize PLR measured based on the response to the longer-wavelength stimulus relative to PLR measured based on the response to the shorter-wavelength stimulus.
7. The pupillometer of claim 1 , wherein each of the first chromatic beam stimulus and the second chromatic beam stimulus stimulates a specific anatomical structure of the eye.
8. The pupillometer of claim 1 , wherein the first chromatic beam stimulus stimulates rods and ganglion cells, and the second chromatic beam stimulus stimulates cones.
9. The pupillometer of claim 1 , wherein the first chromatic beam stimulus and the second chromatic beam stimulus stimulate at least one different anatomical structure of the eye from one another.
10. The pupillometer of claim 1 , wherein the ratios are mapped to a visual field.
11. The pupillometer of claim 1 , wherein the ratios are indicative of the state of health of anatomical structures correlated with individual visual field points.
12. The pupillometer of claim 1 , wherein the ratios are indicative of underlying normal and/or healthy anatomical structures is provided by one or more of the following field point coordinates and expected ratio (0°, nasal, 0.50); (10°, nasal, 0.41); (10°, temporal, 0.45); (10°, up, 0.48); (10°, down, 0.43); (20°, nasal, 0.40); (20°, temporal, 0.33); (20°, up, 0.38); (20°, down, 0.39); (30°, nasal, 0.50); (30°, temporal, 0.44); (30°, up, 0.5); (30°, down, 0.40).
13. The pupillometer of claim 1 , wherein the ratios are indicative of the state of health of an eye associated with glaucoma and retinitis pigmentosa.
14. The pupillometer of claim 1 , wherein the ratios are indicative of the state of health of an eye associated with color blindness.
15. The pupillometer of claim 1 , wherein the test is performed with background luminance providing for light adaptation.
16. The pupillometer of claim 15 , wherein the light adaptation is provided at different controllable periods of the test.
17. The pupillometer of claim 15 , wherein the different controllable periods of the test are selected from the group consisting of: between stimulus presentations, between visual field testing points, between visual field rings, and a combination of one or more of the foregoing.
18. The pupillometer of claim 1 , wherein the quantitative measurement of the PLR comprises pupil constriction amplitude.
19. The pupillometer of claim 1 , wherein the quantitative measurement of the PLR comprises pupil constriction latency.