Should All Patients With Nonarteritic Anterior Ischemic Optic Neuropathy Receive a Sleep Study?

Abstract

A possible association between NAION and OSA was brought to my attention in 2001 by a nephrologist. He had been referred because of bilateral NAION and told me that he believed it was due to OSA. My fellow at the time, Emily Karam, and I started asking patients if they snored. The patients tended to deny it, but their spouses confirmed it. We asked if they stopped breathing, and again, it was denied and then confirmed by spouses. We presented our results at the International Neuro-ophthalmology Society meeting in Dublin in 1999. At the meeting, Daniel Mojon, MD, told me that he also was looking into this possible association. Dan and I published the results of sleep tests in our patients with NAION in the Archives of Ophthalmology in 2002. We found that 12 of the 17 patients with NAION had OSA, whereas 3 of the 17 control subjects had OSA (1). The possible effects of OSA on the eye had been previously described, including an article by Purvin et al on possible papilledema and OSA (2). This was commented on by Lee in a letter to the editor (3). Indeed, Dr. Mojon himself had written about a possible association of OSA with glaucoma (4). This received little attention from neuroophthalmologists, except for a report that suggested that there was no association (5) until 2006, when Palombi et al published a study showing that OSA was more prevalent in their subject group than known risk factors of hypertension, diabetes, hyperlipidemia, and carotid atheromatous disease (6). Li et al subsequently showed that a group of patients with NAION were 2.62 times more likely to have OSA (7), compared with controls. Stein et al showed that if patients having OSA were not treated with continuous positive airway pressure (CPAP), there was a 16% increase in hazard of experiencing NAION (8). In 2013, Arda et al reported a higher prevalence of OSA in patients with NAION vs controls with similar risk factors (9), and Bilgin et al found OSA in 15 of the 27 patients with NAION vs 6 of the 27 in controls (10). This evidence was reviewed by Archer et al in 2013 (11). In 2015, Bandi et al found OSA in 18 of the 19 patients with NAION vs 13 of the 31 controls (12), whereas Aptel et al found that patients with OSA who were noncompliant with CPAP had an increased risk of second eye involvement (13), and Huon et al reported an association between OSA, glaucoma, AION, retinal vein occlusion, central serous retinopathy, and floppy eye lids (14). Wu et al showed that subjects with OSA had a more than 6-fold risk of NAION (15). In 2019, Sun et al and Yang et al showed a strong association between NAION and OSA (16,17). In addition, other researchers have shown that the risk of stroke, hypertension, and atrial fibrillation is greater in individuals with OSA (18). Furthermore, CPAP use can reduce a risk of cardiovascular disease (19). However, so far, there has been no compelling evidence that treatment of OSA with CPAP or surgery reduces the risk of NAION. There may be an increased risk of second eye involvement in patients with NAION who are nonadherent to CPAP treatment (13), but treatment of OSA has not yet been shown to reduce the 15% risk of second eye involvement in NAION (20). Nonetheless, because there is the possibility that treating OSA might be beneficial, I advise all of my patients with NAION to be tested for OSA. It is easy and relatively inexpensive. If one has OSA and is treated, especially with CPAP, they feel better, their partners sleep better, and they are much less likely to fall asleep while operating a motor vehicle (21). Medicine and Health (CLF), University of Sydney, Sydney, Australia; Department of Ophthalmology (TRH), Tufts University, Boston, Massachusetts; Blanton Eye Institute (AGL), Houston, Texas; and Department of Ophthalmology of Visual Sciences (GPVS), Washington University in St. Louis, St. Louis, Missouri.