BILATERAL OPTIC-NERVE CRYPTOCOCCOSIS IN SUDDEN BLINDNESS IN PATIENTS WITH ACQUIRED-IMMUNE-DEFICIENCY-SYNDROME

Purpose. A neuroanatomic study was undertaken to search for the cause of sudden, simultaneously bilateral blindness in a patient with acquir ed immune deficiency syndrome who had cryptococcal meningitis. Methods : Careful gross examination was performed, and microscopic sections we re cut at 50- to 100-mum intervals of the entire visual pathway. Resul ts: Focal cryptococcosis destroyed segments of the right intracanalicu lar optic nerve and the left intraorbital optic nerve adjacent to the optic canal. The meninges were heavily infiltrated by Cryptococcus org anisms around the optic tracts, optic nerves, and optic chiasm; howeve r, only a few scattered cryptococcal organisms were found in the perip hery of the chiasm contiguous with heavy meningeal infection. Blood ve ssels supplying the chiasm appeared normal. Generalized cerebral edema and focal vacuolization of periventricular white matter were evident. Conclusion: The authors believe that sudden, simultaneously bilateral visual loss in this patient was caused by focal but fulminant necrosi s of both optic nerves. However, the presence of cryptococcal organism s throughout the basal meninges and in the sheaths of both optic nerve s suggests that cryptococcosis may produce visual loss by damaging mul tiple areas of the anterior visual pathway.