Number of glaucoma patients will continue to increase, estimate predicts

CHARLESTON, S.C. — In 2010, there will be 60.5 million people with glaucoma worldwide, and that number will increase to nearly 80 million by 2020, said Harry A. Quigley, MD.

Dr. Quigley presented his estimate of the future worldwide prevalence of glaucoma here during the American Glaucoma Society meeting. He noted that these numbers are much higher than previously published estimates.

“You get an idea of all of the world put into one place,” Dr. Quigley said in an interview with Ocular Surgery News.

“Most of the counts of how many people might have glaucoma were using those kinds of blindness prevalence surveys which are heavily weighted in favor of identifying cataracts, but not glaucoma,” he said, referring to an estimate he himself did 10 years ago, as well as others.

His new forecast was based on data only from studies in which the eye was specifically examined for visual acuity and visual field, Dr. Quigley said. The data were divided into those from different ethnic groups, including Chinese, African and those of European descent, he said.

Dr. Quigley said the biggest change in the number of people affected by glaucoma would be detectable in India. He noted that Africans are the most heavily affected by open-angle glaucoma, while angle-closure glaucoma disproportionately affects the Chinese population.

“Angle-closure is one-third as common as open-angle, but blinds almost as many people because it is a more aggressive disease,” Dr. Quigley said.

Overall, he said, glaucoma is the second leading cause of blindness worldwide, disproportionately affecting some populations.

As with cataracts and trachoma, “women are also disproportionately affected by glaucoma,” he said. “World blindness is a problem that women suffer from much more than men.”

Dr. Quigley added that, in the developed world, 50% of glaucoma cases are diagnosed correctly and the patient is properly educated on the disease. In the developing world, “95% of the people have no idea they have glaucoma,” he said.

“I knew my previous work was wrong because we didn’t have the [power] to do the study, so this is a much better estimate,” he said. “I’ll stick by this until we have more studies.”