Overview
Oguchi disease is a rare autosomal recessive form of congenital stationary night blindness (CSNB) distinguished by a unique golden-yellow or gray-white discoloration of the fundus in the light-adapted state that disappears after prolonged dark adaptation — the Mizuo-Nakamura phenomenon. It is caused by mutations in SAG (arrestin) or GRK1 (rhodopsin kinase), both involved in the phototransduction recovery pathway.
Genetics
Two causative genes both involved in rhodopsin deactivation. More prevalent in Japan. Inheritance is autosomal recessive.
| Gene | Locus | Inheritance | Notes |
|---|---|---|---|
| SAG | 2q37.1 | AR | S-antigen (arrestin); most common cause, especially in Japan |
| GRK1 | 13q34 | AR | G protein-coupled receptor kinase 1 (rhodopsin kinase) |
Clinical Presentation
Presenting features
- Congenital night blindness (stationary)
- Mizuo-Nakamura phenomenon (golden fundus in light)
- Normal daytime vision
Long-term
- Generally non-progressive
- Normal visual acuity maintained
- Normal color vision
Diagnosis
- Fundus: Pathognomonic golden-yellow discoloration in light-adapted state
- Dark adaptometry: Markedly prolonged (up to 3+ hours for full rod recovery)
- ERG: Absent or severely reduced rod b-wave; normal cone responses
- Mizuo-Nakamura phenomenon: Fundus normalizes after prolonged dark adaptation
- Genetic testing: SAG and GRK1 sequencing
Current Research & Treatment
No specific treatment is available. The condition is generally stationary and compatible with good quality of life. Research focuses on understanding the phototransduction recovery pathway for broader therapeutic insights.
Active Clinical Trials
The following active clinical trials are investigating treatments for Oguchi Disease. Trial status and enrollment may change; always verify directly on ClinicalTrials.gov.