Spotting Diabetic Eye Damage Risk

Sight-threatening diabetic retinopathy risk may be predicted through annual screening

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Eye damage is one of the many complications of diabetes. Getting an eye exam once a year may help diabetes patients avoid permanent eye damage.

Annual eye exams also may show which diabetes patients are at risk of sight-threatening diabetic retinopathy - a complication of diabetes that causes serious eye damage or blindness, according to recent research.

Diabetic retinopathy is damage to the blood vessels of the eye's retina caused by complications of diabetes. The condition is the main cause of blindness among working-age Americans. When diabetic retinopathy progresses into sight-threatening diabetic retinopathy, patients are at risk of losing their ability to see.

"Get annual eye exams."

Irene M. Stratton, MSc, of Cheltenham General Hospital in the United Kingdom and colleagues found that photographic screening may allow doctors to estimate patients' future risk of developing sight-threatening diabetic retinopathy.

The researchers followed more than 14,000 diabetes patients through 2 years of annual photographic eye exams. That is, patients had their eyes checked once a year for evidence of diabetic retinopathy. Dr. Stratton and colleagues wanted to see if earlier signs of diabetic retinopathy could predict future retinopathy that impairs patients' ability to see.

Results showed that patients with signs of retinopathy during annual eye exams were more likely to develop sight-threatening diabetic retinopathy later down the road.

Patients with diabetic retinopathy in both eyes at both annual screenings had a much higher risk of sight-threatening diabetic retinopathy compared to those with no eye damage at either screening.

Patients with no diabetic retinopathy in either eye at the first screening but retinopathy in one eye in the second screening also had a higher risk of sight-threatening diabetic retinopathy compared to those with no retinopathy at either screening. However, patients with retinopathy in one eye still had a lower risk than those with retinopathy in both eyes at both screenings.

According to the authors, these findings could help doctors and policymakers decide how often diabetes patients should be screened for eye damage.

Of the total 14,554 patients involved in the study, 7,246 did not have diabetic retinopathy at either screening. Of these, 120 developed sight-threatening diabetic retinopathy, which comes out to an annual rate of 0.7 percent.

Of the 1,778 patients with no diabetic retinopathy at the first screening but with diabetic retinopathy in one eye at the second screening, 80 developed sight-threatening diabetic retinopathy. These numbers are equal to an annual rate of 1.9 percent and a hazard ratio of 2.9 when compared to patients without diabetic retinopathy at either screening.

A hazard ratio explains how much an event happens in one group versus another. A hazard ratio of more than 1.0 means that event happens more in the first group than the second. In this case, the event was the development of sight-threatening diabetic retinopathy.

Of the 1,159 patients with diabetic retinopathy at both screenings, 299 developed sight-threatening diabetic retinopathy, which comes out to an annual rate of 11 percent.

Compared to those with no diabetic retinopathy at either screening, those with retinopathy in both eyes at both screenings had a hazard ratio of 18.2 for sight-threatening diabetic retinopathy.

This study was published November 12 in Diabetes Care, a journal of the American Diabetes Association. No conflicts on interest were disclosed.

Reviewed by: 
Review Date: 
November 20, 2012
Last Updated:
November 26, 2012