Oguchi's disease , also called congenital night blindness , [1] is an autosomal recessive [2] form of congenital night blindness associated with discoloration of the fundus and an abnormally slow adaptation to darkness.
| Oguchi's disease | |
|---|---|
| ICD-9 | 368.61 |
| Omim | 258100 |
| Mesh | |
Content
Clinical Features
The disease is present along with non-progressive night blindness from early adolescence or from birth, with normal daylight vision, but with frequent claims by patients about improved sensitivity to light when they stay for a while in a darkened room.
Patient examination reveals normal visual fields, but the fundus has a diffuse or focal appearance, silver-gray or golden-yellow metallic luster and retinal vessels stand out against its background.
Long-term adaptation to the dark for three or more hours leads to the disappearance of this unusual color and the appearance of a normal reddish appearance. This is known as the Mizuo-Nakamura phenomenon and is believed to be due to stick irritation. [3]
Differential Diagnosis
Other conditions with similar manifestations of the fundus include:
- Retinal cone dystrophy
- X-chromosomal retinitis pigmentosa
- Juvenile Macular Dystrophy
These conditions do not cause the Mizuo-Nakamura phenomenon.
Electroretinographic studies
Oguchi's disease gives rise to unique electroretinographic responses in conditions of light and dark adaptation . A-wave and B-wave on separate flash electroretinograms ( ERG ) decrease or are absent during light adaptation, but increase after prolonged adaptation to the dark. There are almost undetectable B-wave sticks with a cattle rate of 0.01 ERG and almost negative with a cattle rate of 3.0 ERG.
Dark adaptation studies have shown that the high-raised thresholds of the rods decrease several hours later, and ultimately come to the restoration of a normal or almost normal level.
The B, S, and L cone systems are normal.
Reasons and Genetics
Some mutations have been implicated in the cause of Oguchi's disease. They include mutations in the arrestin gene or in the rhodopsin kinase gene. [one]
| Type of | Omim | Gene |
|---|---|---|
| Type 1 | 258100 | Sag |
| Type 2 | 613411 | GRK1 |
This condition is more common in individuals of the Japanese ethnic group. [four]
History
Oguchi's disease was described by Tyuta Oguchi (1875–1945), a Japanese ophthalmologist in 1907. The characteristic manifestations of the fundus were described by Mizuo in 1913.
Notes
- ↑ 1 2 OMIM 258100
- ↑ Maw MA , John S. , Jablonka S. , Müller B. , Kumaramanickavel G. , Oehlmann R. , Denton MJ , Gal A. Oguchi disease: suggestion of linkage to markers on chromosome 2q. (English) // Journal of medical genetics. - 1995. - Vol. 32, no. 5 . - P. 396—398. - PMID 7616550 .
- ↑ Hartnett, Mary Elizabeth. Pediatric Retina: Medical and Surgical Approaches Guide to Rare Disorders. - Lippincott Williams & Wilkins, 2004 .-- ISBN 978-0-7817-4782-0 .
- ↑ Oguchi Disease . Foundation Fighting Blindness. Date of treatment May 25, 2007. Archived on April 6, 2007.