What is Retinitis Pigmentosa?
Retinitis pigmentosa (RP) is a group of rare, genetic disorders that involve a breakdown and loss of cells in the retina—which is the light sensitive tissue that lines the back of the eye. Common symptoms include difficulty seeing at night and a loss of side (peripheral) vision.
RP is an inherited disorder that results from harmful changes in any one of more than 50 genes. These genes carry the instructions for making proteins that are needed in cells within the retina, called photoreceptors. Some of the changes, or mutations, within genes are so severe that the gene cannot make the required protein, limiting the cellís function. Other mutations produce a protein that is toxic to the cell. Still other mutations lead to an abnormal protein that doesnít function properly. In all three cases, the result is damage to the photoreceptors.
How Does Retinitis Pigmentosa Progress?
The symptoms of RP typically appear in childhood. Children often have difficulty getting around in the dark. It can also take abnormally long periods of time to adjust to changes in lighting. As their visual field becomes restricted, patients often trip over things and appear clumsy. People with RP often find bright lights uncomfortable, a condition known as photophobia. Because there are many gene mutations that cause the disorder, its progression can differ greatly from person to person. Some people retain central vision and a restricted visual field into their 50s, while others experience significant vision loss in early adulthood. Eventually, most individuals with RP will lose most of their sight.
Is There Treatment for Retinitis Pigmentosa?
There is currently no cure for retinitis pigmentosa but there are now clinical trials working on gene therapy. Patients with a mutation in the RPE65 gene, which can only be confirmed through genetic testing, may qualify for treatment with Luxturna, a gene therapy drug developed by Sparks Therapeutics.
Patients may also benefit from low vision aids to maximize the benefits of existing vision. Having regular eye examinations to measure the progress of the disorder will help parents make informed decisions regarding low vision services and rehabilitation.