[The incidence of nonarteritic ischemic optic neuropathy in the Split-Dalmatia County]

The aim of this study was to determine the incidence of nonarteritic ischemic optic neuropathy (NAION) in the Split-Dalmatia County, Croatia, as part of the Mediterranean region of southern Europe, during a 7-year period (2001-2007). This retrospective study included 87 NAION patients (36 female, median age 68 years, and 51 male, median age 69.5 years) treated at University Department of Ophthalmology, Split University Hospital Center, from January 2001 till December 2007. In each case the diagnosis was confirmed by review of patient records. The annual incidence of NAION was 2.9 per 100,000 (95% CI 1.1-4.8); 3.8 (95% Cl 0.76-6.8) per 100,000 per year in male and 2.5 (95% CI 0.12-4.9) per 100,000 per year in female patients. There was no statistically significant sex difference in the annual incidence of NAION (chi2 = 1.17; P = 0.279). NAION involvement showed a statistically significant male predominance in the > 65 year age group, yielding a relative risk for men vs. women of 1.75. In conclusion, the incidence of NAION in the Split-Dalmatia County was found to be moderate.