Look for signs of depression, anxiety in patients with diabetes and diabetes-related eye disease

Doctors of optometry might consider asking their patients with diabetic retinopathy and diabetic macular edema about their frames of mind.

That's the conclusion of a newly published study, "Association Between Diabetes-Related Eye Complications and Symptoms of Anxiety and Depression," in the July 7 online journal JAMA Ophthalmology. Researchers at the Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne; Singapore Eye Research Institute, National University of Singapore, Singapore; and Duke-National University of Singapore Graduate Medical School, Singapore, conducted the study.

Researchers studied 519 participants who had been diagnosed, on average, 13 years ago. They were given comprehensive eye exams and assessed for the presence and severity of diabetic retinopathy and diabetic macular edema, an advanced form of diabetic retinopathy that occurs when blood and fluid leak into the retina. Patients also were evaluated for visual acuity, as well as signs of depression and anxiety.

Diabetic retinopathy typically shows no symptoms until it becomes severe.

Symptoms include:

• Seeing spots or floaters.
• Blurred vision.
• A dark or empty spot in the center of your vision.
• Difficulty seeing well at night.

What the findings reveal

Fifteen percent (80 participants) tested at the tertiary eye hospital in Melbourne, Australia, had symptoms of depression; another 23% showed symptoms of anxiety.

"The findings of our study demonstrate that severe NPDR (non-proliferative diabetic retinopathy) or PDR (proliferative-stage) and moderate or severe vision impairment, but not diabetic macular edema, were independent risk factors for depressive symptoms in people with diabetes," the researchers say in Science Daily. "The severity and progression of diabetic retinopathy may be a useful indicator to prompt assessment of psychological well-being, particularly in individuals with other risk factors." 

A. Paul Chous, O.D., optometric representative to the National Diabetes Education Program of the National Institutes of Health, who practices in Tacoma, Washington, says diabetes affects every organ system in the body, including psycho-social well-being.

"Many patients with diabetes experience both situational (acute) and chronic depression, and having depression is an independent risk factor for developing type 2 diabetes," Dr. Chous says. "So the relationship is bi-directional. I see this frequently in my patients both with diabetes and no eye disease and those with diabetic eye disease.

"There is no doubt that depressive symptoms worsen," he says. "Vision loss from diabetes-related eye disease interferes with the activities of daily living—something that typically only happens when retinopathy becomes severe or when invasive treatments like photocoagulation and/or intraocular injections become necessary to prevent vision loss."

Some patients may need help coping with the consequences of their eye disease.

"Preventing eye complications from diabetes depends in large measure on patients' abilities to cope with the challenges of managing their disease on a daily basis," Dr. Chous adds. "This is no easy task, especially if patients have pre-existing depression that is exacerbated by a diabetes diagnosis. It is imperative that we work with patients and other providers to address these obstacles early and often. AOA's recently published, evidence-based clinical practice guideline, Eye Care of the Patient with Diabetes Mellitus, recommends that doctors of optometry coordinate care and refer patients to mental health professionals if and when these disorders are suspected."

Dr. Chous has a reservation about the study: It doesn't establish causality, so it's not known if depression led to more severe retinopathy, if the retinopathy leads to more depression, both or neither. Earlier research has shown that patients with depression are more likely to have poorer diabetes control. The depression had been linked to increased risk for severe NPDR and PDR.

He adds, "Poorer diabetes control is also associated with diabetic macular edema but, surprisingly, this new study found no relationship between symptoms of depression and diabetic macular edema. There is no plausible biological explanation for this discordant finding, which, in my view, casts doubt on the authors' conclusions."

For doctors of optometry, the study still provides some practical intelligence on how to help their patients.

"We should be aware of the relationship between depression and diabetes/diabetes-related eye disease, and assess our patients' depressive symptoms, most simply by asking patients if they feel depressed," Dr. Chous says. "Then we should recommend appropriate mental health services in conjunction with primary care physicians and diabetes educators."