VISUAL OUTCOME IN BILATERAL NONARTERITIC ANTERIOR ISCHEMIC OPTIC NEUROPATHY

Background: Nonarteritic anterior ischemic optic neuropathy (NAION) is a common cause of visual loss in the older population, Bilateral NAIO N is a well-documented entity; however, no study to date has compared the visual outcome between affected eyes. Methods: The authors retrosp ectively reviewed the charts of 99 patients with diagnoses of NAION ov er 3 1/2 years. In the 23 patients with bilateral involvement, 16 were included in the study for analysis of final visual outcome between af fected eyes. Snellen acuity, Ishihara color plates, and Humphrey autom ated perimetry were evaluated as the parameters of visual function. De scriptive analysis of the outcome between affected eyes for each param eter is presented as a frequency distribution of pre-defined groups. S tatistical significance is established using nonparametric tests. Resu lts: Bilateral NAION was found in 23% (23/99) of the patients studied, The authors identified a high percent agreement between eyes with reg ard to visual acuity (81% within 3 Snellen lines), color vision (69% w ithin 3 plates), and Humphrey visual field (75% within 5 decibels of m ean deviation). Additionally, there was a statistically significant co rrelation between affected eyes for all three visual parameters: visua l acuity (P = 0.043), color vision (P = 0.001), and Humphrey visual fi eld (P = 0.039). Conclusion: The authors found a high percent agreemen t and statistically significant correlation in final outcome between a ffected eyes of patients with bilateral NAION for visual acuity, color vision, and visual field loss. With a larger series, it may be possib le to predict the visual outcome of the second affected eye based on t he parameters of the first eye.