Inherited Retinal Diseases & Retinitis Pigmentosa

IRDs are vision-threatening genetic disorders (caused by a defect with at least one gene) that affect retinal cells, causing photoreceptor degeneration or dysfunction. There are hundreds of genes that can cause an IRD.

Retinitis Pigmentosa

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About

Inherited retinal diseases (IRDs) are eye diseases that are passed down through gene mutations. They affect the function of the structures of the retina. The retina is responsible for sensing light and passing signals to the brain. A healthy retina is needed for healthy vision.

There are more than 270 genes known to cause IRDs. The most common form of IRD is Retinitis Pigmentosa (RP).

RP actually refers to a group of hereditary diseases, all of which eventually result in severe vision loss. Some of the diseases in the RP family are Usher syndrome, Leber’s congenital amaurosis, rod-cone disease, Bardet-Biedl syndrome, and Refsum disease. Approximately 100,000 people in the U.S. have RP.

Symptoms usually surface during adolescence or young adulthood, although some RP diseases are apparent even in infants. RP progresses at different rates in individuals, but most people with RP are legally blind by age 40. Some forms of retinitis pigmentosa are associated with other disabilities, such as deafness in people with Usher syndrome.

Findings by researchers working with the grant support of Research to Prevent Blindness (RPB) led to the discovery that RP symptoms are caused by the death of cells in the retina. The retina is a light detecting layer inside the eye that sends visual images to the brain.

In most cases of RP, retinal cells called rod photoreceptors are the first to die, followed by cone photoreceptors. Rods are concentrated in the periphery of the retina. They help us see in dim light. Therefore, as the death of rod cells advances, night vision and then peripheral vision progressively disappear. In fact, night blindness is an early symptom of RP. When cones die first, central vision and color vision are impacted before peripheral vision.

A Sight-Restoring Treatment

RPB-supported researchers uncovered causes of retinitis pigmentosa and administered a ground-breaking treatment!

Since 1992, RPB-supported researchers have been looking for a cure for  RP-related diseases. In 2017, the gene therapy Luxturna was approved by the U.S. Food and Drug Administration (FDA) to treat children and adults with mutations in the RPE65 gene (called Leber’s congenital amaurosis). An RPB Career Development Awardee administered the very first treatment.