Jahnavi Sarma
... Read More
By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Cookie Policy.
Researchers say that these eye drops may offer several advantages over existing therapies. @Shutterstock
You have a lens on the front of the eye which focuses images on the inside of the back of the eye. This is the retina, which is covered with nerve cells that convert light to signals. These signals are sent to the brain, which then processes it into images. Proper flow of blood is essential for all this to happen. But sometimes a blot clot may block the retinal vein causing retinal vein occlusion. Sometimes a medical condition may also trigger this blockage.
People with diabetes, hypertension and high cholesterol levels are also at risk of this condition. When this happens, blood and other fluids leak into the retina. This damages specialised light-sensing neurons called photoreceptors. Standard treatment for the condition currently relies on drugs that reduce fluid leakage from blood vessels and abnormal blood vessel growth. But there are significant drawbacks. These therapies require repeated injections directly into the eye. For the patients who brave this daunting prospect, the treatment ultimately fails to prevent vision loss in majority of the cases.
But now, researchers from the Columbia University in the US have developed eye drops that could prevent vision loss after retinal vein occlusion, a major cause of blindness for millions of adults worldwide. Published in the journal Nature Communications, the study suggests that the experimental therapy, which targets a common cause of neurodegeneration and vascular leakage in the eye, could have broader therapeutic effects than the existing drugs.
According to researchers, the new treatment targets an enzyme called caspase-9. Under normal conditions, caspase-9 is believed to be primarily involved in programmed cell death, a tightly regulated mechanism for naturally eliminating damaged or excess cells. However, in studies in mice, scientists saw that when blood vessels are injured by retinal vein occlusion, the caspase-9 becomes uncontrollably activated, triggering processes that can damage the retina. Researchers saw that a highly selective caspase-9 inhibitor, delivered in the form of eye drops, improved a variety of clinical measures of retinal function in a mouse model of the condition.
Most importantly, the treatment reduced swelling, improved blood flow, and decreased neuronal damage in the retina. Researchers say that these eye drops may offer several advantages over existing therapies. Patients may administer the drug themselves and wouldn't have to get a series of injections. Also, the eye drops target a different pathway of retinal injury and thus may help patients who do not respond to the current therapy. The researchers are preparing to test the eye drops in people with retinal vein occlusion during a phase I clinical trial.
(With input from IANS)