What it is
The retina contains two kinds of photoreceptor cells: rods, which handle vision in dim light and across the periphery, and cones, which handle detailed central vision and color. In retinitis pigmentosa a genetic change causes the rods to degenerate first, with the cones typically following much later. As the cells are lost, pigment released from the deteriorating retina settles into characteristic bone-spicule shaped clumps that give the condition its name.
RP is not one disease but a family of them. More than a hundred different genes have been implicated, and the gene involved has a great deal to do with how quickly vision changes and at what age. It affects roughly one person in four thousand.
Symptoms and course
- Night blindness is usually the first symptom — difficulty seeing in a dim restaurant, trouble adjusting when walking from bright sun into a dark room, becoming reluctant to drive at night. It often begins in adolescence or early adulthood.
- Loss of peripheral vision follows, typically as a ring-shaped blind area that gradually widens inward and outward. Because central vision stays sharp, people often do not realize how much field they have lost, and may bump into objects or miss a step at a curb.
- Reduced central vision comes later, and in many people not for decades. Some causes are cataract, macular swelling, or eventual cone involvement.
- Glare and slow adaptation to changing light levels are common throughout.
The pace varies enormously between individuals and between families. Many people with RP retain useful central vision into middle age and beyond.
How we diagnose it
The diagnosis is built from several pieces: a dilated examination showing the characteristic pigment changes and narrowed retinal vessels; visual field testing to map how much peripheral vision remains; OCT to assess the central retina and detect macular swelling; fundus autofluorescence, which often shows a bright ring marking the boundary of surviving retina; and an electroretinogram (ERG), which measures the electrical response of the photoreceptors and is the most sensitive test in early or uncertain cases.
Genetics and family testing
RP can be inherited in several patterns — autosomal dominant, autosomal recessive, or X-linked — and some cases occur with no family history at all. In a subset of patients it is part of a broader syndrome, most commonly Usher syndrome, which also involves hearing loss.
Genetic testing has become an important part of the evaluation. Identifying the specific gene refines what to expect, clarifies the risk to children and siblings, and — increasingly — determines eligibility for gene-specific treatments and clinical trials. We can arrange testing and genetic counseling for you and, where appropriate, for your family.
Treatment and management
There is no treatment that stops the underlying degeneration in most forms of RP, and we will be straightforward with you about that. What we can do is meaningful:
- Gene therapy. An approved gene therapy exists for patients with disease caused by mutations in the RPE65 gene, delivered by injection under the retina. It applies to a small proportion of patients, which is one of the practical arguments for genetic testing.
- Treating complications. Cystoid macular edema is common in RP and often responds to treatment. Cataracts develop early in RP and cataract surgery can produce a genuine improvement in central vision.
- Clinical trials. This is one of the most active areas in retina research, including gene therapy for additional genes, cell-based approaches, and retinal prostheses. We can talk with you about whether a trial is worth pursuing, and about how to find one that matches your genetic diagnosis.
- Supplements. Vitamin A and other supplements have been studied with mixed and debated results, and high-dose vitamin A is not appropriate for everyone — including in some genetic subtypes and in pregnancy. Do not start high-dose supplementation without discussing it with us.
- Sun protection. Good-quality sunglasses with UV protection are sensible, and many patients find amber or plum-tinted lenses reduce glare and improve contrast.
Living well with RP
Practical support matters as much as medical treatment. Low vision rehabilitation can supply magnification, lighting strategies, field-expanding devices, and orientation and mobility training. Screen readers, phone accessibility settings, and audiobook services are genuinely transformative for many patients. Driving needs to be reassessed honestly and periodically as the visual field narrows.
Our resources page lists organizations and local services that can help. We are glad to make referrals and to write the documentation needed for services and accommodations.