Sleep Apnea May Be Linked to Glaucoma, Study Says

People with sleep apnea are at increased risk for glaucoma and should be screened for the eye disease, a new study suggests.

Researchers examined the medical records of more than 1,000 people 40 and older who were diagnosed with sleep apnea between 2001 and 2004, and compared them to a "control" group of more than 6,000 people without sleep apnea.

Those with sleep apnea were 1.67 times more likely to develop the most common type of glaucoma (open-angle glaucoma) within five years of their sleep apnea diagnosis than those in the control group, according to the study, published in the August issue of the journal Ophthalmology.

Glaucoma is the second-leading cause of blindness worldwide. While previous research has found that glaucoma is more common among people with sleep apnea, this study concluded that sleep apnea is an independent risk factor for open-angle glaucoma.

"We hope that this study encourages clinicians to alert obstructive sleep apnea patients of the associations between obstructive sleep apnea and open-angle glaucoma as a means of raising the issue and encouraging treatment of those who need it," wrote Herng-Ching Lin, of the College of Medical Science and Technology at Taipei Medical University in Taiwan, and colleagues in a journal news release.

Sleep apnea -- characterized by disrupted breathing during sleep -- affects more than 100 million people worldwide, and nearly 60 million people have glaucoma. If untreated, glaucoma reduces peripheral vision and eventually may cause blindness by damaging the optic nerve. Only half of people with glaucoma are aware of it, because the disease is painless, and vision loss is typically gradual.

All adults should get a baseline eye exam by age 40, when signs of disease and vision changes may start to occur, the American Academy of Ophthalmology advises.

The study found an association between obstructive sleep apnea and open-angle glaucoma. It did not prove cause and effect.

More information

The U.S. National Eye Institute has more about glaucoma.