People who have both Type 2 diabetes and obstructive sleep apnea (OSA) are at increased risk of developing diabetic retinopathy, according to new research from the University of Birmingham. Approximately 29 million people in the United States are living with Type 2 diabetes, and roughly 22 million Americans have OSA.
OSA is a condition in which breathing stops for 10 seconds or more during sleep, sometimes hundreds of times a night. Diabetic retinopathy occurs when diabetes damages tiny blood vessels in the eye’s retina (the light-sensitive tissue at the back of the eye) and is the leading cause of visual impairment and blindness in working-age adults.
Previous research has demonstrated an association between OSA and diabetic retinopathy. To evaluate the impact of OSA on the development and progression of the eye condition, researchers worked with 230 people with Type 2 diabetes attending two diabetes clinics. People who were already known to have OSA or another respiratory condition were excluded from the study. Participants were evaluated for OSA using a home-based portable device and for diabetic retinopathy using retinal imaging.
The researchers found that the prevalence of diabetic retinopathy was higher in people with OSA, occurring in 42.9% of those with sleep apnea, compared to 24.1% of those without. Additionally, at a follow-up appointment 43 months (roughly 3.5 years) later, 18.4% of those with OSA were found to have developed moderate to severe diabetic retinopathy, compared to 6.1% of those without OSA. The researchers also discovered that people who were treated for OSA using a CPAP machine, which keeps the airways open during sleep by delivering pressurized air through a face mask, had a lower risk of developing advanced retinopathy compared to those who were not receiving sleep apnea treatment.
“We can conclude from this study that OSA is an independent predictor for the progression to moderate or severe diabetic retinopathy in patients with Type 2 diabetes,” stated corresponding study author Abd Tahrani, MD, MRCP (UK), MMedSci, CCT (Endocrinology), PhD. “Following our research, it is important that clinicians treating patients with Type 2 diabetes are aware that their patients who also have OSA are particularly at increased risk of developing advance retinopathy and, hence, appropriate preventative measures should be put in place…. Clinicians should consider testing patients for OSA, as OSA is very common in [people] with Type 2 diabetes.”
Most people with OSA are unaware they have the condition, the researchers note, and could go without a diagnosis — and therefore treatment — for years. Further studies are needed to evaluate how treating OSA could affect diabetic retinopathy, they add.
For more information, see the article “Sufferers of Both Type 2 Diabetes and Sleep Apnea Could Lose Eyesight Within Four Years” or the study’s abstract in the American Journal of Respiratory and Critical Care Medicine. And to learn more about preventing diabetic retinopathy, read “Avoiding Eye Complications” by doctor of optometry A. Paul Chous, MA, OD.