The researchers found that pressure-lowering eye drops reduced by more than 50 percent the development of primary open-angle glaucoma, the most common form of glaucoma and one of the nations leading causes of vision loss. Researchers noted that 4.4 percent of the study participants who received the eye drops developed glaucoma within five years. By comparison, 9.5 percent of the study participants who did not receive the eye drops developed glaucoma. Additionally, personal risk factors, such as older age and African descent, as well as ocular risk factors, such as higher eye pressure, anatomy of the optic nerve, and thinness of the cornea, were associated with the development of glaucoma in study participants.
Elevated eye pressure occurs when fluid that flows in and out of the eye drains too slowly. It is estimated that between 3 million and 6 million people in the United States -- including between 4 and 7 percent of the population older than 40 -- have elevated eye pressure and are at increased risk for developing open-angle glaucoma.
Until now, doctors did not know if treating elevated eye pressure before glaucoma developed could delay the onset of the disease.
This study shows that physicians can make a real impact in preserving the sight of many Americans with ocular hypertension by using proven therapies already at their disposal for glaucoma care, said James Brandt, professor of ophthalmology and lead investigator of the glaucoma study at UC Davis.