Study identifies common pathway disruptions contributing to vision loss

Inherited retinal dystrophies (IRDs) are a leading cause of sight loss in children and adults of working age. 

Mutations leading to the death of light sensing photoreceptor cells at the back of the eye, resulting in blindness, have been identified in over 300 genes. 

Currently only one IRD therapy exists and that is gene specific, meaning only patients with a mutation in that particular gene can receive it. In addition, the visual improvement it gives patients is small and it isn’t yet known how long that lasts. 

Given that developing gene therapies takes a long time, the need for treatments that are effective for all IRDs, no matter the underlying genetic mutation, is extremely important.

With that in mind, researchers at the Institute of Genetics and Cancer (IGC) set out to test if light sensing photoreceptors at the back of the eye develop the same abnormalities in all genetic mutations found in IRDs, and if they die by the same process. 

Using mouse models, they found that the mitochondria in the light sensing photoreceptor cells weren’t working properly, no matter which affected gene was tested. They also found that the processes that clear cells of damaged mitochondria weren’t working properly.

Finally, they discovered the specific cell death pathway that causes the light sensing photoreceptors to die. 

This research is an important first step in developing a one-drug-fits-all approach for IRDs in children and adults.