Overview
Fundus albipunctatus is a rare autosomal recessive stationary retinal dystrophy caused by mutations in RDH5, encoding 11-cis retinol dehydrogenase. It is characterized by a distinctive fundus appearance of numerous small white dots scattered throughout the retina, along with congenital night blindness that is typically non-progressive. Some patients develop cone dystrophy later in life, making it not entirely stationary in all cases.
Genetics
Caused primarily by RDH5 mutations affecting the visual cycle. RLBP1 mutations can cause a similar phenotype (Bothnia dystrophy). Inheritance is autosomal recessive.
| Gene | Locus | Inheritance | Notes |
|---|---|---|---|
| RDH5 | 12q13.2 | AR | 11-cis retinol dehydrogenase; most common cause |
| RLBP1 | 15q26.1 | AR | Retinaldehyde-binding protein 1; causes Bothnia dystrophy variant |
| RDH11 | 14q24.1 | AR | Rare cause; similar phenotype |
Clinical Presentation
Congenital/Childhood
- Night blindness from birth or early childhood
- Prolonged dark adaptation (hours rather than minutes)
- Normal daytime vision initially
Adult onset (subset)
- Progressive cone dysfunction in some patients
- Reduced visual acuity
- Color vision defects
Diagnosis
- Fundus: Numerous discrete white dots at the level of RPE, sparing the macula
- ERG: Absent rod responses that recover after prolonged dark adaptation (>3 hours)
- Dark adaptometry: Markedly prolonged rod adaptation
- Genetic testing: RDH5 and RLBP1 sequencing
Current Research & Treatment
Oral 9-cis retinyl acetate (QLT091001) has shown promise in improving dark adaptation in RDH5-associated fundus albipunctatus. This visual cycle modulator approach is the primary therapeutic strategy under investigation.
Active Clinical Trials
The following active clinical trials are investigating treatments for Fundus Albipunctatus. Trial status and enrollment may change; always verify directly on ClinicalTrials.gov.