Researchers Identify Early Predictor for Glaucoma
Study results suggest new detection tool (Jan. 2)
A new study has found that certain changes in blood vessels in the retina can be an early warning that a person is at increased risk for glaucoma — an eye disease that slowly robs people of their peripheral vision. Using diagnostic photographs and other data from the Australian Blue Mountains Eye Study, the researchers found that patients who had abnormally narrow retinal arteries when the study began were most likely to have glaucoma at the study’s 10-year endpoint.
If confirmed by future research, this finding may give ophthalmologists a new way to identify and treat patients who are most vulnerable to vision loss from glaucoma.
The study was published online in Ophthalmology.
Open-angle glaucoma (OAG) — the most common form of glaucoma — affects nearly three million people in the U.S. and 60 million people worldwide. Vision loss occurs when glaucoma damages the optic nerve. Unfortunately, because glaucoma is asymptomatic, many people don’t know they have the disease until a good portion of their sight has been lost. Early detection is critical to treating glaucoma in time to preserve vision.
The findings of the new study support the concept that abnormal narrowing of retinal blood vessels is an important factor in the earliest stages of OAG. Tracking nearly 2,500 participants, the study found that the risk for OAG at the 10-year mark was approximately four times higher in patients whose retinal arteries had been narrowest when the study began, compared with those who had had the widest arteries.
None of the participants had a diagnosis of OAG at the study's outset. Compared with the study population as a whole, the patients who were diagnosed with OAG by the 10-year mark were older, had higher blood pressure or higher intraocular pressure at the study's baseline, and were more likely to be female. Elevated intraocular pressure is 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,” said lead investigator Paul Mitchell, MD, PhD. “Such a tool would also need to account for blood pressure and other factors that can contribute to blood vessel changes. Early detection would allow ophthalmologists to treat patients before optic nerve damage occurs and would give us the best chance of protecting their vision.”
Source: American Academy of Ophthalmology; January 2, 2013.