January 2, 2013
Glaucoma Research Points To The First Potential Early Indicator
Lee Rannals for redOrbit.com - Your Universe Online
A new study has found that certain changes in blood vessels in the eye's retina can be an early sign that a person may have an increased risk of glaucoma.
The research could eventually provide ophthalmologists with a new tool to identify and treat those who are most vulnerable to vision loss from glaucoma.
Open-angle glaucoma (OAG) affects nearly three million people in the U.S. and 60 million around the world. Vision loss occurs when glaucoma reaches the optic nerve, which is the part of the eye that transmits images from the retina to the brain.
Because glaucoma does not have symptoms, many people do not know they have the disease until they have already lost a large portion of their sight. Early detection of the disease is critical to treating glaucoma in time to save a patient´s vision.
The findings of the new study support the idea that abnormal narrowing of retinal blood vessels is an important factor in the earliest stages of OAG. Nearly 2,500 participants took part in the study, helping researchers to find that OAG risk at the 10-year mark was about four times higher in patients whose retinal arteries had been narrowest when the study began.
None of the study participants had a diagnosis of OAG at the start of the study. Researchers compared the study group as a whole, and the patients who were diagnosed with OAG by the 10-year mark were older, had higher blood pressure or higher intraocular pressure at the start of the study — conditions that are often found in patients with OAG.
"Our results suggest that a computer-based imaging tool designed to detect narrowing of the retinal artery caliber, or diameter, could effectively identify those who are most at risk for open-angle glaucoma," Paul Mitchell, M.D., PhD, of the Centre for Vision Research at the University of Sydney, said in a statement. "Such a tool would also need to account for blood pressure and other factors that can contribute to blood vessel changes."
Mitchell also explained that early detection would allow ophthalmologists to treat patients before optic nerve damage occurs, giving doctors the best chance to protect a patient's vision.
Symptomless eye diseases like glaucoma are an important reason to get a regular eye exam. The American Academy of Opthalmology (AAO)advises that everyone have a complete eye exam by an ophthalmologist at age 40 and to stick to the recommended follow-up exam as scheduled.
The study authors point out that people who have a family history of glaucoma, or who are African American or Hispanic, have a higher risk of developing the disease.