A mimic of the "exact diagnostic sign" of Foster Kennedy.

We observed a patient with bilateral nonarteritic ischemic optic neuropathy presenting with gradual loss of vision in the right eye and initially asymptomatic disk swelling in the left. This atypical picture may create diagnostic difficulty, since sudden visual loss, the major distinguishing feature between Foster Kennedy's original syndrome and "pseudo-Foster Kennedy syndrome" of ischemic optic neuropathy, is lacking.