New research from Taiwan shows that severe sleep apnea is a risk factor for developing diabetic macular edema, a complication of diabetes that can cause vision loss or blindness. Diabetic macular edema was also more difficult to treat in patients with severe sleep apnea. While earlier research showed a weak connection between the two conditions, evidence is mounting that sleep apnea exacerbates underlying eye disease.

When people with diabetes have poor control over their blood sugar levels, the tiny blood vessels at the back of the eye can become damaged. This condition is called diabetic retinopathy and it’s a leading cause of blindness in the United States.

Sometimes, tiny bulges protrude from the blood vessels, leaking fluid and blood into the retina. This fluid can cause swelling or edema in an area of the retina that allows us to see clearly.

Sleep apnea is a sleep disorder in which breathing repeatedly stops and starts, disrupting sleep and causing blood oxygen levels to drop. This drop in oxygen appears to unleash a host of changes in the body that may play a role in injuring blood vessels. People with sleep apnea are at risk of developing hypertension, heart attacks, stroke and type 2 diabetes.

But what about the eyes? Researchers believe that sleep apnea may contribute to the development and worsening of diabetic retinopathy by increasing insulin resistance, elevating inflammation and raising blood pressure, all of which can damage the blood vessels at the back of the eye.

Learn more from the American Academy of Ophthalmology