Biennial eye exam enough in diabetics
By David Douglas
NEW YORK (Reuters Health) - Biennial rather than annual eye screening in people with diabetes without signs of retinal disease is effective and does not lead to any undue delay in treatment, Icelandic researchers report in the December issue of the British Journal of Ophthalmology.
Retinal disease, or retinopathy, is a condition that arises when diabetes damages the tiny blood vessels of the retina, the light-sensitive tissue at the back of the eye. It can lead to blindness.
"Diabetic blindness is one of the most common causes of blindness in the world," investigator Dr. Einar Stefansson told Reuters Health, "and in many countries, for example, UK, the most common cause for working age people going blind."
"The prevalence of diabetic blindness has been and can be decreased by 50 percent to 80 percent with the public health approach." he pointed out. "Thousands of people around the world are blind because of inadequate public health organization in eye care."
To see whether biennial eye exams would suffice for diabetics, Stefansson, along with Dr. E. Olafsdottir of the University of Iceland, Reykjavik studied 296 patients with diabetes and no retinopathy during 1994 and 1995. They were followed, with biennial screenings, for 10 years.
During this observation period, 172 of the patients did not develop diabetic retinopathy. Ninety-six developed mild "non-proliferative" retinal disease, 6 developed clinically significant diabetic macular edema in which fluid accumulates in the part of the retina responsible for central vision; 23 developed "pre-proliferative" retinopathy -- a stage preceding the growth of abnormal blood vessels; and 4 developed proliferative diabetic retinopathy.
The patients who developed macular edema or proliferative retinopathy had been identified at the point at which they had mild non-proliferative retinopathy, and had gone on to an annual screening program before sight-threatening retinopathy developed. Treatment therefore began promptly.
Summing up, Stefansson said: "Diabetic blindness is largely preventable through a public health approach with screening and preventive laser treatment."
Based on the current study, he and colleagues conclude that "biennial screening examinations suffice in both type 1 and type 2 patients with diabetes without retinopathy, and more extended screening intervals may even be feasible."
SOURCE: British Journal of Ophthalmology December 2007.