We report three rare occurrences of late onset dysthyroid optic neurop
athy. We reviewed each case in detail and found that these middle-aged
patients developed onset of optic neuropathy 7 to 12 years following
stabilization of clinically significant, stable ophthalmopathy. There
was no corresponding reactivation of orbital inflammatory symptoms or
signs. Characteristic of a Graves' ophthalmopathy, the vision was resp
onsive to either corticosteroid or surgical decompression, or to a com
bination thereof. None of the patients had diabetes, hypertensive, or
cardiovascular disease. We hypothesize that in these unique cases poss
ible mechanical vascular factors may have induced decompensation of op
tic nerve function in otherwise stable disease.