ELECTROOCULOGRAM CHANGES IN PATIENTS WITH OCULAR HYPERTENSION AND PRIMARY OPEN-ANGLE GLAUCOMA

Recent evidence suggests that retinal hypoxia and ischemia affect the standing potential of the eye and the activity of the photoreceptors. To test whether chronically elevated intraocular pressure would produc e similar effects, we measured electro-oculograms in two groups of pat ients: ocular hypertensive patients and patients with primary open-ang le glaucoma. There were significant differences among the average elec tro-oculogram ratios of these groups compared to age-similar controls. The control observers had an average light-peak/dark-trough ratio of 2.86, the ocular hypertensive patients had an average ratio of 2.44, a nd the patients with primary open-angle glaucoma had an average ratio of 2.07. This indicates that long-term elevations in intraocular press ure can decrease the light peak of the electro-oculogram, even in pati ents with no other evidence of glaucomatous damage. This deficit may h ave its origins in the sensitivity of the outer retina to choroidal is chemia.