Do Diabetics Need Yearly Eye Exams?
Study: Once Every 3 Years May Be Enough for Some
Jan. 16, 2003 -- Many people with type 2 diabetes may not necessarily need annual eye exams to screen for a common eye disease known as diabetic retinopathy. British researchers say only about 30% of people with this type of diabetes are likely to develop related eye problems, and annual exams for those without other risk factors may not be cost-effective.
But other experts say more research is needed before abandoning current recommendations that call for annual screening.
Researchers say screening standards to detect early stages of diabetic eye disease are not uniform worldwide and are based largely on expert opinion rather than evidence-based research. Most countries and the American Diabetes Association recommend yearly screening for patients without symptoms of the disease, but some have questioned the cost-effectiveness of this strategy because widespread screening is expensive.
Diabetic retinopathy is the one of the most common causes of preventable vision loss. But if the condition is caught in the early stages, vision loss can be prevented or delayed.
In this study, Naveed Younis, MD, of the Royal Liverpool University Hospital, UK, and colleagues followed about 7,600 people with type 2 diabetes and tracked the results of their annual eye exams. The rate of potentially sight-threatening disease found in the first year after examination ranged from 0.3% in people with no initial evidence of retinopathy to 15% among patients with moderate forms of the disease at their first examination.
They also found certain factors seemed to increase the risk of developing eye disease. For example, people who had had diabetes the longest were the most likely to progress to sight-threatening eye disease. Specifically, those who had diabetes for more than 20 years had an overall incidence rate of 13.5% over three years, compared to an incidence rate of only 0.7% found among those who had diabetes less than 10 years. They also found that patients initially treated with insulin had the greatest risk for developing sight-threatening vision loss.
Based on their findings, the researchers proposed the following screening intervals, which they say would provide 95% certainty of not missing a case of sight-threatening eye disease:
- Three years -- Type 2 Diabetes patients with no initial evidence of retinopathy
- One year - Those patients with no retinopathy after first exam who use insulin or who have had diabetes longer than 20 years and/or those with signs of early (background) retinopathy
- Four months - Type 2 Diabetics with mild (preproliferative) retinopathy.
In an editorial that accompanies the study, Ronald Klein, MD, MPH, of the department of ophthalmology and visual sciences at the University of Wisconsin, says more research is needed to confirm these results before adopting new, longer intervals for retinal examination.
"The yearly interval in those with no retinopathy has been questioned because screening is not cheap," writes Klein. But he cautions that long intervals between follow-up visits create difficulties in maintaining contact and "may give the patients the impression that visual loss is unlikely and therefore not a concern."
SOURCE: The Lancet, Jan. 18, 2003. • WebMD Medical Reference with Healthwise:"Diabetic Retinopathy"