Less than half of people with diabetes-related eye disease have been told about it, which means they’re also missing out on treatment that could save their sight, U.S. researchers say.

In nationwide surveys of adults with diabetic macular edema - a condition that can ultimately lead to blindness - just 45 percent of respondents said they had been informed by their doctor that diabetes had affected their eyes. Nearly 30 percent already had vision loss in the affected eye.

It’s important to catch the signs of diabetic macular edema (DME) early because it can be treated, Dr. Neil M. Bressler said. He led the study at the Wilmer Eye Institute of Johns Hopkins University School of Medicine and Hospital in Baltimore.

Diabetes commonly causes DME, which is a thickening of the eye’s retina. That change can be detected in an eye exam that includes dilation of the pupils. Left untreated, DME is likely to cause progressive vision loss.

Degeneration of the retina in people with diabetes, known as diabetic retinopathy - which is often caused by DME - is the leading cause of blindness in the U.S., Bressler and his colleagues write in the journal JAMA Opthalmology.

Many U.S. medical authorities recommend annual eye checks for diabetics to monitor early signs of vision problems, but many people with diabetes do not get the proper type or frequency of eye care (see Reuters Health story of December 10, 2013 here: reut.rs/1ck6Zux.

The survey data Bressler’s team used included patient questionnaires and physical examinations, so people with vision loss could be identified even if they themselves were unaware of the changes in their sight.

The researchers considered a subset of 800 people from the survey who reported having diabetes, which affects 25.8 million people in the U.S., according to the Centers for Disease Control and Prevention.

Of the 800 self-reported diabetics, the physical exam confirmed that 238 had diabetic retinopathy without DME and 48 had DME.

Some 60 percent of those with DME said they had undergone an eye exam with pupil dilation within the past year. But only 45 percent said their doctor told them about the changes in their eyes.

Physician and patient behavior seem not to have changed in recent years, despite wonderful new achievements in potential treatments for diabetic eye problems, Dr. Lee Jampol told Reuters Health.

A professor of ophthalmology who studies diabetes and vision at Northwestern University in Chicago, Jampol was not involved with the new estimate.

“This study is very important as it shows that many diabetics are not aware of potential or actual real risk to their eyesight from diabetic retinopathy,” Jampol said.

Physicians and patients need to be more aware of the vision risks involved in diabetes and insist on yearly visits to the ophthalmologist, he said.

Treatment for DMA “typically involves injections of biologics into the middle cavity of the eye that in most cases cause resolution of the swelling with prevention of vision loss in about 90 to 95 percent of cases, and improvement in vision in about 50 percent of cases when the edema involves the center of the retina and is causing vision impairment,” Bressler said.

Patients tend to need about nine injections in the first year with a couple of additional shots over the next two years, and may require laser surgery as well, which can cause the price to vary quite a bit, he said.

“Everyone with diabetes should be referred to an appropriate health care provider who can evaluate the retina for DME or diabetic retinopathy, even in the absence of symptoms, periodically, so that complications which can be treated to prevent vision impairment and blindness can be done,” Bressler said.

SOURCE: JAMA Ophthalmology, online December 19, 2013

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