Retinitis pigmentosa

Definition/diagnostic criteria Retinitis pigmentosa is a heterogeneous group of inherited retinal disorders characterised by progressive peripheral vision loss, night blindness and eventual central vision loss.

Epidemiology Retinitis pigmentosa has an estimated prevalence of 1 in 3,000 to 1 in 4,000 in the UK.

Diagnosis
Clinical features: Patients typically present in adolescence or early adulthood, but onset can vary from childhood to the mid-40s. Initial symptoms often include nyctalopia (night blindness) and peripheral vision loss, leading to ‘tunnel vision’. As the condition progresses, there can be a loss of central vision. Symptom progression is typically slow but can vary between individuals.

Investigations: Diagnosis is primarily clinical, supported by specialist investigations. These include visual field testing, retinal photography, electroretinography (ERG) and Optical coherence tomography (OCT).

Genetic testing is increasingly used to confirm the diagnosis and for genetic counselling.

Treatment There is currently no cure for retinitis pigmentosa, but treatment focuses on managing symptoms using low-vision aids and slowing progression by using sunglasses and other methods to avoid exposure to too much light. Light may make the condition worse.

Regular monitoring and prompt treatment of associated conditions, such as cataracts and macular oedema, is recommended.

Prognosis The prognosis for patients with retinitis pigmentosa is variable and depends on the type of genetic mutation. Most patients will progress to legal blindness by the age of 40-50. There is currently no cure but research is taking place into advanced genetic therapies and supportive technologies