Oguchi disease

General: Autosomal recessive; usually Japa 242f56c nese; form of congenital hemeralopia; one form of essential, congenital night blindness.

Ocular: Fundus has white-gray coloration, especially around the optic disk and in macular region after light exposure (30 minutes to 1 hour); color sometimes is more brown; after 2 to 3 hours in the dark (Mizuo-Nakamura phenomenon), the posterior pole appears normal; the pathogenesis of Mizuo phenomenon has been postulated to be secondary to an excess of extracellular potassium in the retina as a result of a decreased potassium scavenging capacity of retinal Muller cells; central visual acuity and visual fields normal; night blindness always present.

de Jong PT, et al. Mizuo phenomenon in X-linked retinoschisis. Pathogenesis of the Mizuo phenomenon. Arch Ophthalmol 1991; 109:1104-l108.

Magalini S, Scrascia E. Dictionary of Medical Syndromes, 2nd ed. Philadelphia: JB Lippincott, 1981.

Pau H. Differential diagnosis of eye diseases New York: Thieme, 1987.