Obstructive Sleep Apnea Linked to Increased Risk for Glaucoma

People with obstructive sleep apnea (OSA) are far more likely to develop open-angle glaucoma than are those without this common sleep condition, according to the results of a new study, which is the first to calculate the risk of the eye disease among people with sleep apnea.

The authors of the study, led by by Herng-Ching Lin, PhD, of the College of Medical Science and Technology at Taipei Medical University, note in the paper that they are hopeful these results will encourage clinicians to discuss with their OSA patients the association between the sleep disorder and this type of glaucoma, to create awareness and encourage treatment for those who need it.

Conducted by researchers at Taipei Medical University, the retrospective study used a nationwide, population-based dataset to examine the prevalence and risk of the most common form of glaucoma among patients with the most common form of sleep apnea. The researchers reviewed National Health Insurance medical records for more than 1000 patients aged 40 and older throughout Taiwan who received a diagnosis of OSA between 2001 and 2004. They then compared these patients with more than 6000 matched-cohort control patients.

After adjusting for monthly income, geographic region, diabetes, hypertension, coronary heart disease, obesity, hyperlipidemia, renal disease, hypothyroidism, and the number of outpatient visits for ophthalmologic care during the follow-up period, a stratified Cox proportional hazards regression revealed that the hazard ratio for open-angle glaucoma within 5 years of an OSA diagnosis was 1.67 times higher in those who had sleep apnea than in the control subjects.

Previous studies have demonstrated an increased prevalence of glaucoma, which is the second-leading cause of blindness worldwide. This study determined that OSA is not simply a marker for poor health but is actually an independent risk factor for open-angle glaucoma. The relationship between the two conditions is significant, given the large numbers of people worldwide who suffer from them.

Sleep apnea is a chronic condition that blocks breathing during sleep for more than 100 million people worldwide. In OSA, the airway becomes blocked, causing breathing to stop for up to 2 minutes. Symptoms include loud snoring and persistent daytime sleepiness.

Glaucoma affects nearly 60 million people worldwide. If untreated, glaucoma reduces peripheral vision and eventually may cause blindness by damaging the optic nerve. Only half of the people who have glaucoma are aware of it, because the disease is painless and vision loss is typically gradual.

The American Academy of Ophthalmology recommends that all adults should get a baseline eye exam from an ophthalmologist by age 40, when early signs of disease and vision changes may start to occur.

The study results were published in the August 2013 issue of the journal Ophthalmology.

Lin C-C, Hu C-C, Ho J-D, et al. Obstructive sleep apnea and increased risk of glaucoma: a population-based matched-cohort study. Ophthalmology. 2013;120:1559-1564.