Asymmetric retinitis pigmentosa, luetic retinopathy and the question of unilateral retinitis pigmentosa.

A seropositive patient with the fundus appearance of monocular luetic retinopathy is presented. Electrophysiologically, this patient shows a late-onset form of progressive tapetoretinal degeneration (retinitis pigmentosa) presenting in an extremely asymmetric manner. The differential diagnosis of luetic and other inflammatory retinopathies vs. tapetoretinal degenerations is briefly discussed. Features distinguishing unilateral retinitis pigmentosa from bilateral tapetoretinal degenerations are reviewed, and the existence of unilateral retinitis pigmentosa as a genetic entity is questioned. Prolongation of ERG- a- and b-wave implicit times is characteristic of the tapetoretinal degenerations, and normal implicit times in the fellow eye are suggested as an additional criterion for the diagnosis of unilateral retinitis pigmentosa.