• Posted January 23, 2024

Black People Far More Likely to Get Glaucoma, and Genes May Explain Why

Black people are five times as likely as others to develop glaucoma and up to 15 times more likely to be blinded by the degenerative eye disease.

Now, a new study reports that genetics appears to be at least one factor contributing to this increased risk.

Researchers have identified three gene variants that could be fueling Black people's higher glaucoma risk, according to findings published Jan. 18 in the journal Cell.

“Our work is an important step toward defining subgroups of glaucoma, providing the capability for early screening and discovering targetable pathways for personalized therapeutic interventions,” said study co-author Rebecca Salowe, a research project manager with the University of Pennsylvania's Center for Genetics of Complex Disease in Philadelphia.

Glaucoma occurs when fluid pressure starts to increase inside a person's eye, gradually damaging the optic nerve.

For the study, researchers analyzed the genetics of more than 11,200 people of African ancestry.

They discovered two gene variants linked to primary open-angle glaucoma, which is the most common form of the disease.

Open-angle glaucoma affects as many as nine out of 10 Americans who have glaucoma, according to the Cleveland Clinic. It occurs when resistance builds up in the canals that typically drain excess fluid from the eye.

They also found a third variant associated with cup-to-disc ratio, which is a measure of glaucoma severity based on the shape of a person's eye.

Using the variants detected in this study, researchers developed a genetic risk score for glaucoma in Black patients that outperformed a similar risk score based on data from people of European ancestry.

This score could help patients at elevated risk of glaucoma get early screening and treatment for the disease, before it blinds them.

“Glaucoma is a highly familial disease, so premature and irreversible vision loss can affect multiple family members, contributing both to adverse health and economic outcomes,” Salowe said. “With current treatments for glaucoma having limited success, there is an urgent need for large genetic studies to identify novel targets for screening and therapeutic intervention in African ancestry individuals.”

Until now, only 2% of studies linking genetics to specific diseases has involved people whose ancestry is tied to Africa, the researchers noted.

"This work highlights the essential role of diversity in genetic research,” said lead researcher Shefali Setia Verma, an assistant professor of pathology and laboratory medicine at Penn Medicine.

More information

The Cleveland Clinic has more about glaucoma.

SOURCE: University of Pennsylvania, news release, Jan. 18, 2024