Photostress test | |
---|---|
Synonyms | PSRT |
Purpose | can differentiate between retinal and post retinal disease |
Photostress recovery time (PSRT) is the time taken for visual acuity to return to normal levels after the retina has been bleached by a bright light source. Photostress recovery time measurement procedure is known as photostress test. Normal recovery time is about 15–30 seconds. [1]
The photostress test is a simple, easy and quick clinical technique that can differentiate between retinal ( macular) and postretinal (e.g. optic nerve) disease. [2]
The photo stress test is clinically useful in diabetes, [3] glaucoma, [3] macular degeneration [4] etc. Diabetic retinopathy affects the microvasculature of the inner retina and causes neurodegeneration. Several studies reported that PSRT is elevated in people with diabetes. [3] Recovery time is more in macular diseases (50 seconds or more) than postretinal (e.g.optic nerve) diseases. [1] Elevated PSRT has also been found in primary open angle glaucoma (POAG) which is characterized by progressive death of the retinal ganglion cells. [3] Amblyopic eyes with normal fundus also have normal recovery time. [5]
Ophthalmoscope or alternative source of light (e.g.penlight), [2] stop watch, distance vision charts like a Snellen chart.
The main disadvantage of the test is that there is no standardization of the procedure. [6] The effect of aging on recovery time is also thought as a disadvantage, but it is still under discussion since some studies found increased PSRT with age, and others did not find any significant effect. [3]
Photostress test | |
---|---|
Synonyms | PSRT |
Purpose | can differentiate between retinal and post retinal disease |
Photostress recovery time (PSRT) is the time taken for visual acuity to return to normal levels after the retina has been bleached by a bright light source. Photostress recovery time measurement procedure is known as photostress test. Normal recovery time is about 15–30 seconds. [1]
The photostress test is a simple, easy and quick clinical technique that can differentiate between retinal ( macular) and postretinal (e.g. optic nerve) disease. [2]
The photo stress test is clinically useful in diabetes, [3] glaucoma, [3] macular degeneration [4] etc. Diabetic retinopathy affects the microvasculature of the inner retina and causes neurodegeneration. Several studies reported that PSRT is elevated in people with diabetes. [3] Recovery time is more in macular diseases (50 seconds or more) than postretinal (e.g.optic nerve) diseases. [1] Elevated PSRT has also been found in primary open angle glaucoma (POAG) which is characterized by progressive death of the retinal ganglion cells. [3] Amblyopic eyes with normal fundus also have normal recovery time. [5]
Ophthalmoscope or alternative source of light (e.g.penlight), [2] stop watch, distance vision charts like a Snellen chart.
The main disadvantage of the test is that there is no standardization of the procedure. [6] The effect of aging on recovery time is also thought as a disadvantage, but it is still under discussion since some studies found increased PSRT with age, and others did not find any significant effect. [3]