Parainfectious optic neuritis. Report and review following varicella.

Severe loss of vision and bilateral optic disc edema occurred in a 10-year-old girl 38 days after the rash of varicella first appeared and subsequent encephalitis developed. Recovery of visual function was nearly complete, but optic atrophy persisted. Parainfectious optic neuritis following other viral infections, with the exception of herpes zoster, has a similar clinical profile: delayed onset, severe visual loss, optic disc edema, bilaterality, good recovery, and residual optic atrophy. Conduction delays in our patient's patterned visual evoked potentials implicated demyelination within the optic nerves. The often favorable recovery, frequency of delayed onset, and bilateral involvement of the optic nerves support an autoimmune process in the pathogenesis of parainfectious optic neuritis.