Glaucoma patients are likely to lose more of their vision if they suffer minor strokes, a three-year study in Hong Kong has found.

Glaucoma, or damage to the optic nerve, is the second leading cause of blindness and experts estimate that more than 60 million people in the world will suffer from it by 2010.

The Hong Kong study found that glaucoma patients who suffered minor strokes were 61 percent more likely to lose more of their vision than other glaucoma patients who did not suffer minor strokes.

These (minor) strokes in the brain are likely to affect the eye, Dexter Leung, ophthalmology clinical assistant professor at the Chinese University of Hong Kong, told a news conference on Tuesday.

Minor strokes -- or silent cerebral infarctions (SCI) -- are disturbances in blood supply to the brain that sufferers are not even aware of and they may lead to loss of some brain function.

The study, published in the July issue of the journal Ophthalmology, involved 286 patients with glaucoma.

Through brain scans, the researchers found that nearly 30 percent of these patients suffered SCIs over a three-year period. And those who suffered SCIs were 61 percent more likely to lose more of their vision than those who did not suffer SCIs.

The lead author of the study, Professor Dennis Lam, said stroke prevention was important to stop the deterioration of glaucoma.

It's important to have systemic control by controlling risk factors of stroke, such as diabetes, hypertension, and adopting healthier lifestyles (like diet and exercise), said Lam, who is also from the Chinese University of Hong Kong.