Retinitis Pigmentosa
What is Retinitis Pigmentosa?
Retinitis pigmentosa is a group of rare, inherited eye disorders that cause progressive damage to the retina, the light-sensitive tissue at the back of the eye, making it hard to see. In RP, the light-sensing cells (photoreceptors), particularly the rods and later the cones, gradually break down and stop functioning, leading to gradual vision loss.
What are the Causes of Retinitis Pigmentosa?
Retinitis pigmentosa is caused by genetic mutations that affect the function of photoreceptor cells in the retina. These mutations can be inherited in different patterns - autosomal dominant, autosomal recessive, or X-linked - and lead to gradual degeneration of the retina. The faulty genes disrupt the production or function of proteins needed for healthy vision, eventually causing cell death and vision loss.
What are the Symptoms of Retinitis Pigmentosa?
Symptoms of retinitis pigmentosa include:
- Night blindness (difficulty seeing in low light).
- Loss of peripheral vision (tunnel vision).
- Gradual decline in central vision in later stages.
- Difficulty adjusting between light and dark environments.
- Possible light sensitivity and color vision changes.
Symptoms often appear in childhood or adolescence, but the rate and severity of vision loss vary.
How is Retinitis Pigmentosa Diagnosed?
Retinitis pigmentosa is diagnosed through a comprehensive eye examination that may include:
- Visual field testing to detect peripheral vision loss.
- Electroretinography (ERG) to measure retinal cell function.
- Ophthalmoscopy to look for characteristic retinal changes, such as pigment clumping.
- Genetic testing to identify the specific mutation and inheritance pattern.
What are the Treatment Options for Retinitis Pigmentosa?
Treatment options for retinitis pigmentosa focus on slowing progression, managing symptoms, and maximizing remaining vision, since there is currently no complete cure. Common approaches include:
- Vitamin A palmitate supplements (in specific doses, under medical supervision) to slow degeneration in some patients
- Gene therapy, such as voretigene neparvovec, for certain RPE65 mutations to restore or improve retinal function
- Retinal implants (bionic eyes) to partially restore vision in advanced cases
- Low-vision aids such as magnifiers, special glasses, and electronic devices
- Protective sunglasses to reduce light damage to the retina
- Supportive rehabilitation, including orientation and mobility training
- Ongoing clinical trials for stem cell therapy, neuroprotective drugs, and optogenetics
