The new treatment targets an enzyme called caspase-9, says Carol M. Troy, MD, PhD, professor of pathology & cell biology and of neurology in the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain at Columbia University Vagelos College of Physicians and Surgeons, who led the studies. 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.

In studies of mice, the Troy lab discovered that when blood vessels are injured by retinal vein occlusion, caspase-9 becomes uncontrollably activated, triggering processes that can damage the retina.

Eye Drops Prevent Retinal Injury

The Troy lab found 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.

“We believe these eye drops may offer several advantages over existing therapies,” says Troy. “Patients could administer the drug themselves and wouldn’t have to get a series of injections. Also, our eye drops target a different pathway of retinal injury and thus may help patients who do not respond to the current therapy.”