The silent threat of glaucoma, a condition that can progress from blind spots to complete blindness, often goes undetected, particularly among minority populations unaware of their genetic risk factors. In a groundbreaking development, a study published today in Cell presents the largest-ever analysis of genetic risk factors for glaucoma in people of African ancestry, revealing several previously unidentified genetic variants linked to the condition.
Terri Young, a pediatric ophthalmologist and geneticist at the University of Wisconsin–Madison, praises the study for addressing an unmet need in assessing glaucoma risk, especially in minority populations. Currently, doctors rely on age and family history as primary indicators, but this falls short, given the susceptibility of individuals of African ancestry, who are up to five times more likely to develop glaucoma than their white counterparts.
As the leading global cause of blindness, glaucoma affects 44 million people, with fluid pressure buildup in the eye posing a significant risk. Treatment involves medication, lasers, or scalpels to relieve pressure, though none reverse existing vision loss. Shockingly, up to 40% of glaucoma cases exhibit normal eye pressure, rendering traditional pressure-reducing methods ineffective.
Individuals of African ancestry face a disproportionately higher risk, being up to 15 times more likely to go blind due to glaucoma and developing the condition at an earlier age. Despite these disparities, most genetic studies have focused on individuals of European ancestry. The recent study, led by Joan O’Brien of the University of Pennsylvania, aimed to rectify this by enrolling over 6000 people of African ancestry, half of whom had glaucoma.
Historical challenges in enrolling Black participants in genetic studies were overcome through community engagement, building trust with initiatives such as church outreach and collaboration with Black community leaders. The extensive study, incorporating demographic data and vision tests, included over 11,200 individuals of African ancestry—making it the largest of its kind.
The researchers identified 46 genomic locations associated with glaucoma, unveiling three genetic variants, including two previously unknown, responsible for the most common form in this population. Significantly, these variants showed a pronounced effect in individuals with African ancestry.
The study's impact extends beyond identification, as scientists developed a polygenic risk score based on the genetic data. This score outperformed previous models developed for individuals of European ancestry, effectively identifying the 20% of patients at the highest risk of developing glaucoma.
Looking ahead, the research team plans to collaborate with the Los Angeles Latino Eye Study to explore gene variants associated with glaucoma in the Latino population. This breakthrough promises a paradigm shift in glaucoma management, paving the way for targeted medications and improved patient care. Eydie Miller-Ellis, a co-author of the study, emphasizes the potential of this information to revolutionize our understanding and intervention in glaucoma, marking a crucial step toward a promising future in patient care.
More: https://www.science.org/content/article/new-risk-genes-glaucoma-identified-people-african-ancestry
