It was recently discovered that eye drops can be effective in delaying the onset of glaucoma in individuals with high eye pressure. These results mean that treating people at higher risk for developing glaucoma may delay and possibly prevent the disease.

In a study performed at Shiley Eye Center, led by Robert N. Weinreb, M.D., Director of Shiley’s Hamilton Glaucoma Center, and 21 other leading glaucoma centers throughout the United States, it was 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 affecting more than 3 million Americans. Upon release of this data, Dr. Weinreb was invited to speak before a congressional committee on the origin and scope of glaucoma.

The study, called the Ocular Hypertension Treatment Study, examined 1636 people 40-80 years of age who had elevated eye pressure but no signs of glaucoma. Half of the participants received daily commercially available eye drops.

Results showed 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. Eighty-six percent of the patients did not develop glaucoma.

Glaucoma occurs when the optic nerve is damaged. In many individuals, increased pressure in the eye plays an important role in this damage, but is not always a factor. The damage to the optic nerve causes loss of peripheral (side) vision. As the disease worsens, the field of vision gradually narrows and blindness can result.

(Visual pathway)

(Eva Kroneker, COA, OHTS clinical trial coordinator)

“Though commonly misunderstood as a disease of ‘increased eye pressure’ the hallmark of glaucoma is loss of the optic nerve fiber, regardless of the pressure,” states Dr. Weinreb. In fact, almost 90% of the study participants, all who had an elevated eye pressure, did not develop glaucoma within the five-year study period.

Elevated eye pressure results when the fluid within the eye drains too slowly, gradually increasing pressure inside the eye. It is estimated that between more than six million people in the U.S. have elevated eye pressure and are at increased risk for developing glaucoma. Until now, doctors did not know if treating elevated eye pressure before glaucoma developed could delay the onset of the disease. This study provides some important information to consider in reaching a decision about treatment.

Other significant risk factors found to be associated with the development of glaucoma included older age and individuals of African descent, who are three to four times more likely to develop glaucoma than Whites. Additionally, ocular risk factors, certain characteristics in the anatomy of the optic nerve, and thinness of the cornea are also linked with developing glaucoma.

"This study demonstrates that some patients with high eye pressure do benefit from eye pressure lowering eye drops. However, some patients have a low risk for developing glaucoma and do not necessarily need treatment.", said Dr. Weinreb. Participating in the study with Dr. Weinreb was Rigby Slight MD and Eva Kroneker, who coordinated the Shiley site.