Overview
Retinitis pigmentosa (RP) is an umbrella term for inherited disorders causing progressive visual loss, primarily affecting the peripheral retina, causing tunnel vision. Its name describes the fundoscopic findings.
RP may occur in the eyes only, or be part of a syndrome with associated non-ocular features. For example, RP is associated with Alport’s syndrome.
Epidemiology
- RP has a global prevalence of around 1 in 5000
- Men are slightly more affected due to X-linked forms being expressed more in men than women
- Autosomal recessive forms tend to present in early adolescence
- Autosomal dominant forms tend to present in a patient’s 20s
- Most patients will present by the time they are 30 years old
Presentation
- Impaired night vision – often the first sign
- Tunnel vision
- Fundoscopy may show:
- Bony spicule pigmentation
- Vascular narrowing
- Abnormal pallor of the optic disc
Investigations
- Visual acuity assessment
- Visual field testing
- Electroretinogram – diagnostic test
- The retinal equivalent of an ECG or electroencephalogram (EEG)
- Shows increased latency and decreased amplitude
Management
There is no cure. Vitamin A (retinol) supplementation and fish oils may be considered to slow progression.
Prognosis
- RP is progressive, however, total blindness is uncommon as the macula is relatively preserved
