Risk of Stroke After NAION
American Journal of Ophthalmology, April 2019
Does an association exist between stroke and nonarteritic anterior ischemic optic neuropathy (NAION)? Study findings have been conflicting. Park et al. looked at a national database to better understand whether NAION could be a precursor to stroke. Among their Korean study population, NAION itself was not linked to greater risk of stroke.
This population-based retrospective study included more than 400,000 beneficiaries listed in the National Health Insurance Service–National Sample Cohort database (NHIS–NSC) from 2002 to 2013. Time-varying covariate Cox regression models were used to assess the relationship between incident NAION and the likelihood of subsequent stroke. Model 1 included only incident NAION as a time-varying covariate; model 2 included model 1 and demographic data; and model 3 included model 2 as well as comorbidity, comedication, and Charlson Comorbidity Index score. Results were expressed as the effect (hazard ratio [HR]) of NAION on the subsequent development of stroke.
The researchers found that NAION occurred in 1,125 patients, and stroke occurred in 16,998. In model 1, NAION was not associated with greater risk of subsequent stroke (HR, 1.31). For models 2 and 3, findings were similar after adjustment for demographic and confounding factors (HR, 1.19 and 1.10, respectively).
The authors acknowledged that the NHIS–NSC database does not include details on metabolic profiles, physical activity, body mass index, alcohol consumption, or smoking—all of which affect stroke risk. Even so, the study sample is large and population-based, which minimized selection bias. The results of sensitivity analyses were consistent with those of the main analyses, as were results of matching based on propensity score. Thus, the authors concluded, the etiologic mechanisms of NAION and stroke appear to differ.
The original article can be found here.