A large retrospective, longitudinal cohort study based on the national health insurance database of Taiwan found significant correlation between nonarteritic anterior ischemic optic neuropathy and obstructive sleep apnea.
The data covered the period 1996-2013, during which 8,488 cases of obstructive sleep apnea (OSA) were reported. In this population, the overall rate of nonarteritic anterior ischemic optic neuropathy (NAION) was 0.36%, while in the 33,952 subjects of the control group the rate was 0.2%.
Multivariate COX regression analysis showed that the subjects with OSA had a significantly higher risk of developing NAION within the 18 years of the study. The biggest difference in risk rate between patients with OSA and controls was found in the 30- to 39-year-old age group, while the peak percentage of NAION in the OSA group was in the 70- to 79-year-old age group.
NAION presents with sudden-onset, painless visual loss on awakening in the morning, due to ischemic damage of the optic nerve with variable degrees of severity.
The mechanism by which OSA may provoke NAION is unclear. It might include hypoxia and compression of the optic nerve or oxidative stress impairing the functionality of the arteries that nourish the optic nerve. Variations in ocular perfusion pressure and imbalance between vasoconstrictive and vasodilatory agents might also play a role, the authors explained.
The strong association between NAION and OSA found in this study suggests that OSA may contribute to the development of NAION.
“Therefore, OSA should be screened in NAION patients and then treated once the diagnosis is confirmed given that management for OSA may help prevent new NAION events in the fellow eye,” the authors wrote. – by Michela Cimberle
Disclosure: The authors reported no relevant financial disclosures.