Three-Year Screening for Diabetic Retinopathy Appears Safe

NEW YORK (Reuters Health) May 27 - Patients with mild type 2 diabetes can be safely screened for sight-threatening vision problems every three years instead of annually or biannually, Swedish researchers say.

Opinions regarding optimal screening intervals differ. In the United States, annual screening for diabetic retinopathy is recommended. In Sweden, screening every two years has long been the standard.

Since 2006, however, doctors at Skane University Hospital in Malmo have used three-year screening intervals - and Dr. Elisabet Agardh and Dr. Poya Tababat-Khani reported that experience online May 11th in Diabetes Care.

The total cohort consisted of 1,691 patients in their mid-50s with type 2 diabetes for about six years and no detectable retinopathy in two fundus photographs.

Of the 1,322 patients available for follow-up three years later, 960, or 73%, were still retinopathy-free and 362 (27%) had developed mild or moderate retinopathy. None had severe nonproliferative or proliferative retinopathy.

Three subjects had signs of macular edema, two in both eyes and one in one eye. Only one of those five eyes required laser treatment.

"Thus, sight-threatening retinopathy occurred in 5 of 2,644 eyes, or 0.19%, but affected visual acuity in only 1 eye (0.04%)," Dr. Agardh and Dr. Tababat-Khani report.

These findings, they say, indicate that it's safe to extend the screening interval to three years in patients with type 2 diabetes and no retinopathy at the initial screen.

They note, however, that the patients in the cohort had mild diabetes of short duration and their metabolic control was good. To reduce the risk of dropout, patients were given screening reminders well in advance of their scheduled follow-up visit, which led to good compliance. With a three-year screening interval, patients might be more prone to disregard their follow-up screening appointment, they investigators note.

In 2010, Swedish National Board of Health and Welfare changed its general recommendation for screening intervals from two to three years in patients with type 2 diabetes and a low risk of progression from no retinopathy to sight-threatening retinopathy.

"The results of the current study support that advice, but it may be necessary to individualize the intervals for patients with severe diabetes," the authors say.

SOURCE: http://bit.ly/klzm5w

Diabetes Care 2011.