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Oguchi disease

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Oguchi disease
Classification and external resources
ICD-9 368.61
OMIM 258100

Oguchi disease, also called congenital stationary night blindness, Oguchi type 1 or Oguchi disease 1,[1] is an autosomal recessive[2] form of congenital stationary night blindness associated with fundus discoloration and abnormally slow dark adaptation.

Clinical featuresEdit

Oguchi disease present with nonprogressive night blindness since young childhood or birth with normal day vision, but they frequently claim improvement of light sensitivities when they remain for some time in a darkened environment.

On examination patients have normal visual fields but the fundi have a diffuse or patchy, silver-gray or golden-yellow metallic sheen and the retinal vessels stand out in relief against the background.

A prolonged dark adaptation of three hours or more, leads to disappearance of this unusual discoloration and the appearance of a normal reddish appearance. This is known as the Mizuo-Nakamura phenomena and and is thought to be caused by the overstimulation of rod cells.[3]

Differential diagnosisEdit

Other conditions with similar appearing fundi include

These conditions do not show the Mizuo-Nakamura phenomenon.

Electroretinographic studiesEdit

Oguchi's disease is unique in its electroretinographic responses in the light- and dark-adapted conditions. The A- and b-waves on single flash electroretinograms (ERG) are decreased or absent under lighted conditions but increase after prolonged dark adaptation. There are nearly undetectable rod b waves in the scotopic 0.01 ERG and nearly negative scotopic 3.0 ERGs.

Dark-adaptation studies have shown that highly elevated rod thresholds decrease several hours later and eventually result in a recovery to the normal or nearly normal level.

The S, M and L cone systems are normal.

Cause and GeneticsEdit

Autorecessive

Oguchi disease has an autosomal recessive pattern of inheritance.

Several mutations have been implicated as a cause of Oguchi disease. These include mutations in the arrestin gene or the rhodopsin kinase gene.[1]

Type OMIM Gene
Type 1 258100 SAG
Type 2 613411 GRK1

The condition is more frequent in individuals of Japanese ethnicity.[4]

HistoryEdit

It was described by Chuta Oguchi (1875-1945), a Japanese ophthalmologist, in 1907. The characteristic fundal appearances were described by Mizuo in 1913.

ReferencesEdit

  1. 1.0 1.1 OMIM 258100
  2. PMID 7616550 (PMID 7616550)
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  3. Hartnett, Mary Elizabeth; Antonio Capone, Michael Trese (2004). Pediatric Retina: Medical and Surgical Approaches Guide to Rare Disorders, Lippincott Williams & Wilkins.
  4. Oguchi Disease. Foundation Fighting Blindness. URL accessed on 2007-05-25.

External linksEdit


Template:Cell membrane protein disorders Template:Deficiencies of intracellular signaling peptides and proteins

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