Eyedrops Fend Off Blindness
Eyedrops that lower pressure inside the eye can delay the onset of glaucoma, the second-leading cause of blindness, according to new research that should influence the way many at-risk patients are treated.
The drops were used to treat a condition called ocular hypertension, in which fluid in the front chamber of the eye doesn’t drain properly and pressure builds up. When the pressure rises sufficiently, it can press on the optic nerve and kill cells responsible for vision, crossing the threshold to become glaucoma. Other factors contributing to glaucoma risk include age, thickness of the cornea and the anatomy of the optic nerve.
So-called open-angle glaucoma, the most common form of the disease, affects about 2.2 million Americans 40 and older; doctors estimate 2 million more may have it. The leading cause of blindness among African Americans, open-angle glaucoma develops slowly, often without symptoms. By the time it’s detected, a patient’s field of vision may have narrowed.
But by intervening with medication in patients with elevated eye pressure readings, doctors reduced by more than 50% the number of cases that developed into open-angle glaucoma after five years.
Researchers, led by Dr. Michael Kass, an ophthalmologist at Washington University in St. Louis, studied 1,636 people from age 40 to 80 who had high ocular pressure, but no vision changes or abnormalities in the eye’s structure associated with glaucoma. Half were given daily eyedrops; the others were just monitored. The medication lowered the pressure of the treated group by about 20%.
“It is significant that this modest 20% reduction in eye pressure had such an important protective effect,” said Kass.
Until the study results were published in the June issue of Archives of Ophthalmology, doctors didn’t know for sure whether reducing high eye pressure could delay or prevent glaucoma, although about 1.5 million people were being treated prophylactically anyway.
The study was supported by the National Eye Institute, the National Center on Minority Health and Health Disparities, the Research to Prevent Blindness foundation and Merck Research Laboratories.
