Visual Fields in Low-Tension Glaucoma, Primary Open Angle Glaucoma, and Anterior Ischemic Optic Neuropathy

Abstract

We compared the type and location of visual field defects in 94 eyes with low-tension glaucoma, 225 eyes with primary open angle glaucoma, and 160 eyes with anterior ischemic optic neuropathy. The distribution of defects in two varieties of glaucoma were similar; both involved the upper half of the visual field more frequently, the lower half less frequently, and central vision much less frequently than did anterior ischemic optic neuropathy. These differences in distribution of field defects were independent of the severity of field loss and of patient age. The most frequent defects in both low-tension glaucoma and primary open angle glaucoma were superior nasal defects and superior arcuate scotomas; the most frequent defects in anterior ischemic optic neuropathy were inferior hemifield loss and central scotomas.

These findings suggest that the pathogenic mechanism for optic nerve damage in low-tension glaucoma resembles that of primary open angle glaucoma more than it resembles that of anterior ischemic optic neuropathy.