Genetic test developed to predict onset of glaucoma

A group of researchers from Australia has formulated a genetic test that could detect people's susceptibility towards developing glaucoma, which is a debilitating ocular disease that can potentially make its sufferers go blind.

The team of scientists suggests that there are 107 genes that are responsible for the onset of this condition.

They are looking forward to 20,000 people's participation in their Genetics of Glaucoma Study in order to help them find more genes involved in the disease.

Glaucoma is characterised by progressive damage and degeneration of the optic nerve which also causes gradual loss of vision. It is the leading cause of irreversible blindness worldwide and is predicted to affect 76 million people by 2020.

There is still no proven cure for the disease, but treatment can reliably slow or halt deterioration in most cases. Up to 50 per cent of those affected are not even aware.

Stuart MacGregor, lead researcher and the head of QIMR Berghofer's Statistical Genetics Group, Associate Professor, said that identifying new genes allowed them to develop a glaucoma polygenic risk score (PRS) that can predict who is likely to get the eye disease.

"Glaucoma is a genetic disease and the best way to prevent the loss of sight from glaucoma is through early detection and treatment," MacGregor defined.

"Our study found that by analysing DNA collected from saliva or blood, we could determine how likely a person was to develop the disease and who should be offered early treatment and/or monitoring," he added.

He also feels that unlike existing eye health checks that are based on eye pressure or optic nerve damage, the genetic test can be done before damage begins so that regular screening can be put in place.

Clinical lead researcher and academic head of the Department of Ophthalmology at Flinders University, Professor Jamie Craig, said that the study results gave hope that mass screening for glaucoma could be offered in the future.

"There are Australians who, if they'd had appropriate treatment a few years earlier, wouldn't have gone blind," said Professor Craig, who is also a consultant ophthalmologist.

"One in 30 Australians has glaucoma, but most people only find out they have it when they go to the optometrist because they are losing vision, or for a general eye check," shares Craig, continuing, "Early detection is paramount because existing treatments can't restore vision that has been lost, and late detection of glaucoma is a major risk factor for blindness."

He said that glaucoma can arise at any age but most of those affected are in their 50s or older, so their aim is to offer blood tests to people of that age to find out if they are at risk, and then hopefully act on it.

This test is likely to be helpful in identifying those who would benefit from a more aggressive intervention such as surgery rather than simple eyedrops.

The researchers are hoping to get in touch with people with a family history of the disease. "We want to know who will get glaucoma, and for those who are susceptible, we want to be able to pinpoint at what age they're going to get it," said Associate Professor MacGregor.

The researcher concluded, "That would allow us to develop a personalised approach for earlier treatment of high-risk individuals, and means people at lower risk could have less intensive monitoring and treatment. This would have benefits for patients, doctors and the health care system with reduced interventions and reduced costs.