Annual eye exams are recommended for those with diabetes, as they can help reveal hidden signs of vision problems related to the condition, but nearly 60% of those with diabetes skip the exam, according to a new study.
The exam is crucial to preserve vision, said study leader Anna Murchison, MD, MPH, director of the eye emergency department at Wills Eye Hospital in Philadelphia. She presented the data at the American Academy of Ophthalmology annual meeting in October in Chicago. 
"Diabetes can lead to changes in the small blood vessels of the body, including inside the eye," Dr. Murchison told OnTrack Diabetes. "These changes can result in abnormal blood vessel formation, leakage of fluid, and bleeding inside the eye with an end result of decreased vision. Some of these changes can be treated more effectively when recognized early," she said. A full eye exam is needed, she said, because some of the changes have no symptoms, so the person is unaware of the problem. It's best to dilate the pupil, so the eye doctor can get a good look inside the eye, experts agree.
Under the current recommendations from the American Academy of Ophthalmology, those diagnosed with type 1 diabetes should receive their first full eye exam to look for diabetes-related problems within five years of the diagnosis and then annually. Those with type 2 should get a full eye exam when they are diagnosed and then annually.
Dr. Murchison's team collaborated with the Centers for Disease Control and Prevention, which funded the study. The researchers reviewed the charts of nearly 2,000 patients age 40 and older with type 1 or type 2 diabetes. Over a four-year period, the researchers found that 58% of the patients did not have regular follow up exams. Least likely to follow the recommendations were those with less severe diabetes, smokers and those with no symptoms of eye problems.
One complication of diabetes is diabetic retinopathy, in which damage to the retina occurs due to the diabetes. But it isn't the only potential vision issue found in those with diabetes, Dr. Murchison said. Those with diabetes are also more likely to develop glaucoma (damage to the optic nerve), cataracts and macular edema (buildup of fluid in the macula, an area in the center of the retina.) "All of these are treatable disorders which [left untreated] can impact vision and, often, quality of life," Dr. Murchison said.
Catching diabetes-related eye conditions early can definitely help to preserve vision, said Rahul Khurana, MD, a clinical spokesperson for the American Academy of Ophthalmology and an ophthalmologist in Mountain View, Ca. He commented on the study.
If you catch problems, early, he said, ''95% of vision loss can be prevented."
Currently, more than three million people in the U.S. have vision problems due to diabetic retinopathy, according to Dr. Murchison, and that number is expected to double by 2050.
Why don't people get the exams on schedule? Dr. Murchison speculated that cost, finding a doctor and transportation to the doctor might be barriers. Some of the changes in the eye don't have symptoms, she added, so people may not be aware. And she believes some people may fear the exam process or getting the results.
Despite those barriers, annual eye exams could greatly reduce the toll of diabetes-related vision problems, eye experts agree.