Eye doctors can often treat glaucoma successfully if they catch it early, but a new study suggests that ophthalmologists can sometimes wait before treating those at risk of developing the disease.
If their ophthalmologists choose to postpone treatment, certain patients with higher-than-normal pressure in the eye won't need to take prescription anti-glaucoma eye drops, potentially for years.
"In the past, doctors were left to their own judgment, which is fine," said study author Dr. Michael A. Kass, chairman of the department of ophthalmology and visual sciences at Washington University in St. Louis. "But it's nice to have some judgment that's backed up by some hard evidence."
Glaucoma, caused when pressure in the eye damages the optic nerve, can lead to impaired vision and blindness. Older people and blacks are at especially high risk.
To measure their risk, ophthalmologists measure eye pressure, often with a puff of air or blue light.
The pressure exists because "there's fluid produced in the eye, and it needs to filter out. It keeps your eye from being soft and mushy, and allows you to keep the structural roundness necessary for you to see," explained Dr. Alfred Sommer, a professor of ophthalmology and dean emeritus of the Bloomberg School of Public Health at Johns Hopkins University in Baltimore.
People with higher pressure are at risk of developing glaucoma, and eye doctors can give preventive eye drops to patients when their eye pressure is high. But the drops can be expensive and annoying, Sommer said.
So, what to do with the millions of people in the United States who have high eye pressure with no sign of glaucoma damage?
In the new study, Kass and his colleagues tracked 1,636 people with higher than normal eye pressure. The patients were randomly assigned to be observed or to receive medication.
Patients in the medication group were treated for a median of 13 years. After a median of 7.5 years without treatment, those who were observed received medication for a median of 5.5 years. In the medication group, the risk of developing glaucoma was 16 percent, compared with 22 percent in the observation group.
Some patients "are at low risk, and they don't seem to benefit much from early preventive treatment. The people who are high risk may benefit," Kass said.
If glaucoma does develop, it can often be treated through medication, laser treatments and other strategies, he added.
Overall, the findings shouldn't change how eye doctors currently handle high eye pressure, said Sommer, who wrote a commentary accompanying the new study.
"My own preference, unless someone is a really high-risk outlier, is to just watch them rather than subject them to pressure-lowering medication," Sommer said.
Patients who are diagnosed with high eye pressure should ask their doctor whether they're at high risk or if they can just be monitored, he suggested.
However, "you can't disappear," he said. "You need to have an examination once a year to make sure there hasn't been any progression."
The findings are published in the March issue of the Archives of Ophthalmology.