Patients with sleep apnea were 1.67 times more likely to develop glaucoma than patients without apnea, according to a study that compared more than 1000 apnea patients with more than 6000 age-matched participants. The study was published in the August issue of Ophthalmology.
Ching-Chun Lin, MA, from the Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taiwan, and colleagues relied on data from the Taiwan Longitudinal Health Insurance Database 2000, matching 1012 apnea patients aged 40 years and older with 6072 control patients of similar age, sex, and urbanization. A patient was considered to have apnea only if there were a record of him or her undergoing a sleep study. The researchers counted a glaucoma diagnosis only if the patient were prescribed medication.
"The fact that the authors required this [evidence of diagnosis] really increases the validity of their results," Ahmad A. Aref, MD, assistant professor of ophthalmology, University of Illinois Eye and Ear Infirmary, Chicago, told Medscape Medical News. Dr. Aref, who authored a review on glaucoma and sleep earlier this year was not involved in the current study.
"Armed now with this study, clinicians should start to question their patients about sleep apnea," Dr. Aref said. "I would treat it like other established risk factors for glaucoma, such as having a family member with glaucoma, or having high eye pressure, or being of African-American race. I would start to think seriously about grouping sleep apnea with those more established risk factors."
Lin and colleagues found that the incidence rate of open-angle glaucoma among patients diagnosed with apnea was 11.26 per 1000 person years (95% confidence interval [CI], 8.61 - 14.49) compared with 6.76 per 1000 person years (95% CI, 5.80 - 7.83) for patients without an obstructive sleep apnea (OSA) diagnosis.
The adjusted hazard ratio (HR) for a glaucoma diagnosis within 5 years of being diagnosed with apnea was 1.67 (95% CI, 1.30 - 2.17; P < .001) after adjusting for monthly income, geographic region, diabetes, hypertension, heart disease, obesity, hyperlipidemia, renal disease, hypothyroidism, and number of outpatient visits for ophthalmologic care.
The adjusted HR for a glaucoma diagnosis among women in the 5 years after a sleep apnea diagnosis was 1.55 (95% CI, 1.04 - 2.31). For men, the adjusted HR was 1.45 (95% CI, 1.02 - 2.16).
"This study gives the most evidence to date that sleep apnea is a risk factor for OAG," Parag Gokhale, MD, from Virginia Mason Medical Center, Seattle, Washington, told Medscape Medical News in an email. Dr. Gokhale, the spokesman for the American Academy of Ophthalmology, was not involved in the current research. Among the study's strengths, he said, was the researchers' decision to control for other possible causes of glaucoma, something several previous studies failed to do.
In this study, participants in the OSA group had higher levels of hypertension (P < .001), diabetes (P < .001), heart disease (P < .001), hyperlipidemia (P < .001), obesity (P < .001), renal disease (P < .001), and migraine (P < .001), the researchers found. Prevalence of hypothyroidism was equal in each group.
W. Christopher Winter, MD, medical director, Martha Jefferson Hospital Sleep Medicine Center, Charlottesville, Virginia, says this study should influence sleep specialists to include eye health in the list of concerns for apnea patients.
"With the risk [for glaucoma] 3 to 5 years out as high as it is, recommending a baseline eye exam would be a good thing. Eye exams, if your vision is good, usually fall by the wayside. I think I would add that," Dr. Winter said.
The authors noted several limitations to the current study including a lack of severity information, such as apnea-hypopnea index scores or respiratory disturbance index scores, which would have allowed them to determine whether risk for glaucoma increased with the severity of the sleep apnea.
Furthermore, it is possible that the control group included people with undiagnosed sleep apnea.
The authors, Dr. Aref, Dr. Gokhale, and Dr. Winter have disclosed no relevant financial relationships.
Ophthalmology. 2013;120:1559-1564. Abstract
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Cite this: Glaucoma: Sleep Apnea May Raise Risk - Medscape - Aug 15, 2013.