Definition for Oguchi's disease

Oguchi's disease, first described by Chuta Oguchi in 1907, is a rare autosomal recessive disorder characterized by congenital stationary night blindness and a unique morphological and functional abnormality of the retina. more

Oguchi's disease, first described by Chuta Oguchi in 1907, is a rare autosomal recessive disorder characterized by congenital stationary night blindness and a unique morphological and functional abnormality of the retina. Patients have non-progressive night blindness since young childhood with normal day vision, but often report improvement of light sensitivities when they remain long in the dark environment; dark-adaptation study demonstrates that highly elevated rod thresholds decrease several hours later and eventually result in a recovery to the normal or nearly normal level. The fundus has a diffuse or patchy appearance, silver-gray or golden-yellow metallic sheen and the retinal vessels stand out in relief against the radiant background. A prolonged dark adaptation of three hours or more, leads to disappearance of the unusual discoloration of the normal reddish appearance, called Mizuo-Nakamura phenomenon. Oguchi's disease is also unique in the electroretinographic responses in the light- and dark-adapted condition. B wave amplitude is reduced in rod response and cone response is normal. Recent identification of the arrestin gene mutation, in chromosome 2q in patients with Oguchi's disease may account for the characteristic fundus and functional abnormality. As rhodopsin kinase works with arrestin in shutting off rhodopsin after it has been activated by a photon of light, it has been proposed that some cases of Oguchi disease are due to defects in rhodopsin kinase. less