Retinitis pigmentosa (RP) refers to a group of rare inherited retinal dystrophies that cause progressive vision loss due to photoreceptor degeneration and black pigmentation spots on the retinal pigment epithelium. The condition can eventually lead to total blindness after decades.
More than 3,000 mutations in over 60 different genes or loci are known to cause non-syndromic RP. The most common mutations vary by inheritance pattern: RHO gene mutations for autosomal dominant RP, USH2A gene mutations for autosomal recessive RP, and RPGR and RP2 gene mutations for X-linked RP.
The primary symptom is progressive vision loss, typically beginning with night blindness and eventually affecting central vision. Central vision loss may occur at any age due to macular oedema or photoreceptor loss. Additional symptoms include cataracts (severity is age-dependent) and reduced colour vision.
Currently, treatment focuses on slowing disease progression through vitamin A palmitate and lutein-DHA supplementation, oral acetazolamide or topical dorzolamide for cystoid macular oedema, and lens extraction for cataracts that reduce visual acuity. Specialised sunglasses and optical aids can also help manage symptoms.
