Fewer Eye Exams for Diabetics?
Feb. 15, 2000 (Atlanta) -- Blindness and diabetes often go hand in hand. Will more diabetic patients go blind if eye-exam guidelines are relaxed? A new study suggests that most non-insulin-dependent diabetes patients don't need annual testing, but experts disagree over its implications. The study, published in the Journal of the American Medical Association, suggests that testing low- and moderate-risk patients every other year would save money -- and slightly increase the number of people who go blind.
Sandeep Vijan, MD, lead author of the study, tells WebMD that the money saved could be used to find a way to reduce blindness among diabetics. "This doesn't mean we shouldn't screen people; clearly, screening works," says Vijan, assistant professor of internal medicine at the University of Michigan and an investigator at the Veterans Affairs Health Services Research Center in Ann Arbor. "But are we doing exams that don't need to be done? You are talking about saving a billion and a half dollars -- we are not talking about small amounts of money here. If we dedicated that money to improving the system, we would do a lot better," he says.
Vijan and colleagues created a mathematical model to simulate the U.S. population of non-insulin-dependent (called type 2) diabetics older than 40 years. The model shows that the current screening program costs $5.54 billion per year -- $1.56 billion more than screening every other year and $2.34 billion more than screening every third year.
To improve screening, Vijan would divide type 2 diabetes patients into groups according to age and by how well they keep their glucose levels under control. Patients at the lowest risk of blindness are elderly patients with good glucose control; those at the highest risk are younger patients with poor glucose control. According to the model, low-risk patients have only a 1% chance of going blind, even with no screening. Those that do become blind would lose their sight during the last three years of their lives. High-risk patients have a 22% chance of going blind without screening -- and even with annual screening, their risk is 10%. Those who become blind would lose their sight for the last eight years of life.
"Certainly annual screening is very effective in the high-risk group," Vijan says. For other patients, he advises a combination of glucose control and less frequent screening.
In an interview to provide objective comment, endocrinologist Leann Olansky, MD, tells WebMD she agrees every-other-year screening is adequate for some low-risk patients -- if doctors can be sure exactly which patients these are. "Identifying the low risk patients is difficult," she says. "But the concern is that the greatest number of patients are those at intermediate risk, and where do they belong? I think [Vijan] is probably correct, generally, but I think there is going to be somebody slipping through there who will end up blind because they did not get treated early enough."