Glaucoma is one of the leading causes of visual deterioration on the planet, affecting millions of people worldwide, though it is more prevalent among some ethnic groups.
For years, experts have attempted to determine why African-Americans have a higher risk of developing glaucoma than Caucasians, although it seems that experts in the US may have finally found out why this occurs.
Specialists at the Washington University School of Medicine in St Louis claim that oxygen levels are significantly higher in the eyes of African-American glaucoma patients than in Caucasians who have the condition.
In a report published in the Archives of Ophthalmology, they theorise that more oxygen may lead to damage in the eye"s drainage system in the eye, resulting in elevated pressure which in turn damages the optic nerve and causes blindness.
First author Dr Carla Siegfried pointed out that the report is the first clue about the link between race and risk of glaucoma, which is approximately six times more common in African-Americans than Caucasians, while blindness caused by glaucoma is 16 times more likely.
The expert explained: "Our findings suggest there may be physiologic differences in oxygen metabolism between African-Americans and Caucasians.
"In our studies, we were not looking specifically at African-Americans, but the racial difference in oxygen levels was significant, and we believe this observation deserves further study."
Siegfried, who is also professor of ophthalmology and visual sciences at Washington University, said she is not surprised that oxygen may plays a major role in the development of glaucoma, given it could be a source of "free radicals" that damage cells.
As with eye diseases such as cataracts, glaucoma is directly associated with ageing, as is oxidative stress, which is an imbalance between these "free radicals" and antioxidants".
This, in turn, is linked to the ageing process and several other age-related diseases such as cardiovascular and neurodegenerative conditions, she noted.
"However, more study is required. When we understand the underlying reason for elevated oxygen and how it may damage the eye, we will be in a better position to develop ways to prevent this disease," the expert said.
by Emily Tait