Optic atrophy. Differential diagnosis by fundus observation alone
J. D. Trobe, J. S. Glaser and J. C. Cassady
In order to assess the contribution of fundus examination to the
differential diagnosis of acuqired optic neuropathy, five ophthalmologists
viewed 163 fundus stereophotographs of nine disease entities as "unknowns."
Glaucoma, central retinal artery occlusion (CRAO), and ischemic optic
neuropathy (ION) were diagnosed by at least one observer with an accuracy
above 80%. The remaining conditions (optic neuritis; compressive,
traumatic, and hereditary optic neuropathies) were correctly identified
with less than 50% accuracy. Retinal arteriolar attenuation and sheathing
were most helpful in differentiating CRAO and ION. Although pathologic disc
cupping often identified glaucoma, it was also seen in 20% of eyes with
optic atrophy not associated with glaucoma. Excavation was more profound in
glaucoma than in nonglaucomatous optic atrophy, the latter demonstrating
relatively greater neuroretinal rim pallor. In 6% of nonglaucomatous optic
atrophy eyes, however, disc cupping was misdiagnosed as "glaucomatous."
Only 11% of eyes with previously documented papillitis or ION left clues
that allowed observers to identify preexisting disc swelling.
