Epidemiology of benign essential blepharospasm: A nationwide population-based retrospective study in Taiwan.

IMPORTANCE: This study provides a nationwide, population-based data on the incidence of benign essential blepharospasm in Asian adults. BACKGROUND: To describe the incidence, patient demographics, and risk factors associated with benign essential blepharospasm. DESIGN: Population-based retrospective study. PARTICIPANTS AND SAMPLES: A total of 1325 patients with benign essential blepharospasm were identified. METHODS: Patients with diagnosis of blepharopsasm between January 2000 and December 2013 were sampled using the Longitudinal Health Insurance Database 2000. Secondary blepharospasm that may be related to neurological, trauma, and ocular surface disease were excluded. MAIN OUTCOME MEASURED: Multivariate conditional logistic regression was used to estimate the odds ratios for potential risk factors of benign essential blepharospasm. RESULTS: The mean annual incidence was 0.10 per thousand (0.07 per thousand for males, and 0.12 per thousand for females). The peak incidence was in the 50 to 59-year-old age group (0.19 per thousand). People living in urban regions have more risk of developing blepharospasm comparing to people living in less urban regions (p <0.01). White-collar workers also have higher chance of having blepharospasm (p<0.001). Significant difference between control group and case group in hyperlipidemia (p <0.001), sleep disorders (p <0.001), mental disorders (depression, anxiety, obsessive compulsive disorder) (p <0.001), dry eye-related diseases (dry eye, Sjogren's syndrome) (p <0.001), Parkinson's disease (p <0.004), and rosacea (p <0.021) were also identified. CONCLUSIONS AND RELEVANCE: Higher level of urbanization, white-collar work, sleep disorders, mental health diseases, dry eye-related diseases, Parkinsonism, and rosacea are possible risk factors for benign essential blepharospasm.