In the hopes of finding a way to predict a person’s risk of developing glaucoma, the National Institutes of Health’s National Eye Institute (NEI) funded research that has discovered 133 genetic variants related to intraocular pressure (IOP).* These genetic variants have been found to predict glaucoma risk with 75% accuracy, which would most benefit people at high risk for glaucoma to help greatly improve disease—and thus, vision loss—prevention.

What they did

Researchers analyzed IOP readings and genotype data from 139,555 participants across three large groups of people, all of whom were of European descent. Their goal was to identify which of the variants that increase IOP truly were associated with a rise in the risk of glaucoma. 

From there, the study looked at the presence of the variants in 4,000 people with glaucoma and 30,000 people without glaucoma from the NEIGHBOR (NEI Glaucoma Human genetics collaBORation) consortium. This is the largest database of people with a known glaucoma status and is funded by the NEI.

What they found

The data revealed 133 genetic variants associated with the risk of elevated IOP, of which 68 genetic variants had not been previously linked to IOP. 

Their findings show that future genetic tests to detect these variants could identify high-risk individuals for glaucoma. These people could greatly benefit from early intervention to prevent glaucoma and related vision loss, as glaucoma is a leading cause of vision loss and blindness in the U.S.

What it means

In its early stages, glaucoma can cause peripheral vision loss or tunnel vision. When it goes undetected, glaucoma can progress and lead to blindness. Knowing one’s genetic status lets clinicians better understand who is at a high risk of glaucoma. In turn, this allows them to closely monitor eye pressure from early on and prescribe any necessary interventions earlier on to prevent disease progression.

“Unexpectedly, we found an almost direct correlation between the magnitude of the genetic variants’ effect on eye pressure and their effect on glaucoma risk. In other words, IOP appears to be the overriding factor that determines whether someone develops glaucoma,” said Janey Wiggs, M.D., Ph.D., co-author of the study. “Substantial evidence shows that the earlier you treat people, the better they are going to do in terms of maintaining and preserving useful vision.”

While 75% test accuracy isn’t perfect, “it’s a significant improvement over our current ability to predict a person’s risk for glaucoma,” Wiggs stated. Future studies will look at whether these same genetic variants can also predict the age of onset, severity, and other disease characteristics for glaucoma.

*National Eye Institute. (2018, May 31). NEI funded researchers identify 133 genetic variants that predict glaucoma risk. https://www.nei.nih.gov/about/news-and-events/news/nei-funded-researchers-identify-133-genetic-variants-predict-glaucoma-risk