Nonglaucomatous excavation of the optic disc
J. D. Trobe, J. S. Glaser, J. Cassady, J. Herschler and D. R. Anderson
In order to test the hypothesis that glaucomatous and nonglaucomatous optic
disc cupping can be distinguished ophthalmoscopically, three
ophthalmologists experienced in assessing optic dics were asked to view
fundus stereophotographs as "unknowns". Of 29 eyes with nonglaucomatous
optic atrophy, 13 (44%) were misdiagnosed as showing glaucoma by at least
one observer. Of four optic disc features specifically analyzed,
neuroretinal rim pallor proved to be 94% specific for nonglaucomatous
atrophy, while focal or diffuse obliteration of the neuroretinal rim was
87% specific for glaucoma. These two signs are the most useful in making
the distinction. Thinning of the rim was more common in glaucoma than in
nonglaucomatous atrophy, but was only 47% specific for glaucoma. Laminar
dots were present in both types of excavation.
