The Secret to Saving Sight in Retinitis Pigmentosa

Retinitis pigmentosa (RP) is a leading cause of inherited blindness globally. It causes a slow but steady loss of both rod and cone photoreceptor cells. These cells are crucial for seeing in the dark and during the day, respectively. Most RP-causing genes only affect rods, but cones also die off later. This secondary cone death might be due to metabolic issues. Photoreceptors need a lot of energy. They use up glucose and produce lactate. The retinal pigment epithelium (RPE) helps manage this by moving glucose to photoreceptors and removing lactate. In RP, when rods die, lactate levels drop. This might cause the RPE to reduce glucose supply, starving the cones. A recent study explored a potential solution. They used a virus to deliver a gene called MCT2 to the RPE. MCT2 helps the RPE take in lactate and pass on glucose. The goal was to keep cones alive and functioning. In rat and mouse models of RP, this approach showed promising results. Cones survived longer and worked better.The study also used advanced imaging to track lactate and glucose levels in the eye. They saw changes in these levels when MCT2 was present, suggesting that cone survival is linked to RPE metabolism. This finding opens up a new path for treating RP, one that might work regardless of the specific gene involved. However, it's important to note that this research is still in its early stages. While the results are encouraging, more work is needed before this approach can be used in humans. The study also doesn't fully explain how changes in metabolism affect cone survival. More research is needed to understand this complex process. One thing is clear: metabolism plays a significant role in RP. By targeting the RPE and its metabolic functions, researchers might find a way to preserve vision in people with RP. This approach could potentially benefit many, as RP is caused by mutations in many different genes. A gene-agnostic therapy would be a game-changer in the field of inherited retinal degenerations.