[Pigmented paravenous retinochoroidal atrophy--a case report].

Pigmented paravenous retinochoroidal atrophy is a rare dystrophy, which is usually asymptomatic and limited to the paravenous area. Due to the slow progression of eye fundus changes, typically without the macular involvement, pigmented paravenous retinochoroidal atrophy is not thought to be a vision-threatening ocular disease. We report a case of a 64-year-old man with sudden unilateral reduction of vision and binocular diplopia, diagnosed with bilateral pigmented paravenous retinochoroidal atrophy. The diagnosis was based on a characteristic fundus appearance, additionally accompanied by the bilateral mild macular changes, minor optic disc pallor and moderate retinal artery narrowing. The presented case posed a diagnostic challenge due to the sudden onset and atypical manifestation.