A team of scientists from Singapore have identified three new genes associated with primary angle closure glaucoma, a leading cause of blindness among the Chinese population, a local television channel reported on Monday.

The discovery made by the team of scientists from the Singapore Eye Research Institute, which is affiliated with the National University of Singapore, was the first in the world to link glaucoma with genes, Channel NewsAsia said.

Professor Aung Tin, deputy director of Singapore Eye Research Institute, said one of the three genes discovered affects vascular permeability, and the other gene is a collagen-related gene.

"But the third gene, we do not know what it does," the researcher added.

Glaucoma occurs when there is nerve damage from pressure in the eyeball. It can be divided into two main categories, namely the open angle chronic glaucoma and the primary angle closure glaucoma (PACG).

Nine in 10 Asians who have glaucoma suffer from PACG. PACG is a type of glaucoma where visual loss progresses very quickly. It is usually more prevalent among those aged 60 years or older.

Having the first of the risk genes makes a person 30 percent more susceptible to the disease. The second gene, by 50 percent. If a person has all three genes, the risk may increase to up to 300 percent.

The researchers said they are hoping that the findings will lead to better understanding of the disease mechanism and causation so that in the future novel therapies can be developed for the condition.

They are also hoping that medical workers shall be able to " better identify people at risk for the disease, so that we can intervene, and do a preventive treatment for them."

A 2010 study showed that glaucoma affected 60 million people worldwide, and about half of them are from Asia.

PACG was found to be the leading cause of blindness in Chinese people because of an anatomical risk present in the eyeball of a Chinese, where the angle between the iris and the cornea is narrower than a person of another race.