Incidence of Sympathetic Ophthalmia after Inciting Events: A National Database Study in Japan.

ABSTRACT

PURPOSE: To analyze the incidence of sympathetic ophthalmia (SO) after inciting events (eye trauma or intraocular surgery). DESIGN: Retrospective cohort study. PARTICIPANTS: Patients experiencing inciting events between 2012 and 2019. Onset of SO was defined as the first date of SO diagnosis. METHODS: Using a nationwide administrative claims database in Japan, we calculated the cumulative incidence of SO after inciting events stratified by sex, 10-year age groups, and a categorical variable of primary or repeated, reflecting the history of inciting events in the past year (no inciting events, inciting events without trauma, or inciting events with trauma) using the Kaplan-Meier approach. We also estimated the adjusted hazard ratio (aHR) by Cox regression. We then restricted the population to those with only 1 inciting event during the observation period to investigate the pure effect of each inciting event. MAIN OUTCOME MEASURES: Cumulative incidence of SO over 60 months. RESULTS: A total of 888 041 inciting events (704 717 patients) were eligible. The total number of SO cases was 263, and the cumulative incidence of SO was 0.044% over 60 months. Female sex was not associated with onset of SO (aHR, 1.01; 95% confidence interval [CI], 0.79-1.29; P = 0.95). The group 40 to 49 years of age showed the highest incidence of 0.104% among the age groups (aHR vs. ≥80 years of age group [0.041%], 2.44 [95% CI, 1.56-3.80]; P < 0.001). Repeated inciting events with and without trauma showed higher incidences of SO (0.469% and 0.072%, respectively) than primary inciting events (0.036%) (aHR 11.68 [7.74-17.64] and 2.21 [95% CI, 1.59-3.07], respectively); P < 0.001 and P < 0.001, respectively). The incidence of SO after vitrectomy was much lower than after trauma (0.016% vs. 0.073%), and the incidence after scleral buckling was even lower. CONCLUSIONS: The cumulative incidence of SO over 60 months was estimated to be 0.044% at minimum. Repeated inciting events, especially those with trauma, increased the risk of SO developing. Trauma was 4 to 5 times as likely to induce SO than vitrectomy. The present findings will be valuable for counseling patients about the risks of SO after trauma and before performing intraocular surgeries.