Abstract
Optic atrophy with excavation of the disk and especially with marginal cupping, as seen in glaucoma, is a puzzling condition when the intra-ocular tension is persistently low. In these cases a diagnosis of glaucoma is generally made notwithstanding the subnormal tension. This curious and contradictory condition has been explained in the following ways : Some authors believe that during a preceding stage the tension has been sufficiently raised to cause cupping, but that now the tension is permanently low. E. Fuchs1 suggested that the lamina cribrosa in these cases is particularly weak, for some unknown reason, and cannot resist even the usual normal pressure. He did not believe that a simple optic atrophy appears from the beginning with a deep excavation and nasally displaced blood vessels, and thought it more likely that a combination of optic atrophy and glaucoma simplex is present. Elschnig2 denied the weakness of