A potential treatment for a leading cause of blindness may be on the way, after experts in the US revealed that they have shed light on the cause of death of photoreceptor cells in retinitis pigmentosa.
Experts at the Angiogenesis Laboratory at Massachusetts Eye and Ear Infirmary have, for the first time, identified the mode of death of cone photoreceptor cells in an animal model of the inherited condition, which causes irreversible vision loss due to the degeneration of photoreceptor cells in the eye called rods and cones.
The groundbreaking study was led by Dr Demetrios G. Vavvas and has further identified the receptor interacting protein (RIP) kinase pathway as a potential target for developing treatment for vision loss in patients with the condition.
In the study, published an issue of Proceedings of the National Academy of Sciences Early Edition, experts note that vision loss from retinitis pigmentosa often begins with loss of night vision, due to death of rods, followed by loss of peripheral and central vision, due to the death of both rods and cones.
Such vision loss can have a significant impact on people's daily lives, such as affecting their ability to read or drive a car, and affects more than one million people around the world.
According to the study, Vitamin A supplementation and an omega-3 rich diet can slow visual decline resulting from the disease, but does not completely stop disease progression.
Using an animal model of retinitis pigmentosa, investigators studied whether RIP kinase mediated necrosis is involved in the death of photoreceptor cells, and found for the first time that it does play a part in cone degeneration and that a deficiency of RIP kinase reduced cone loss.
In addition, researchers found that treatment with a drug that inhibits RIP kinase significantly delayed cone cell death and preserved cone photoreceptors.
Commenting on the study, Dr Vavvas said: "Though the precise mechanisms involved in RIP kinase inducing necrosis remain unknown, our finding that necrosis results in cone cell death puts us one step closer to understanding this disease and, more importantly, moves us one step closer to being able to provide novel therapies to millions of patients with vision loss."