The Incidence and Risk Factors of Medial and Inferior Orbital Wall Fractures in Korea: A Nationwide Cohort Study

Abstract

Purpose: We aimed to investigate orbital wall fracture incidence and risk factors in the general Korean population. Method: The Korea National Health Insurance Service–National Sample Cohort dataset was analyzed to find subjects with an orbital wall fracture between 2011 and 2015 (based on the diagnosis code) and to identify incident cases involving a preceding disease-free period of 8 years. The incidence of orbital wall fracture in the general population was estimated, and the type of orbital wall fracture was categorized. Sociodemographic risk factors were also examined using Cox regression analysis. Results: Among 1,080,309 cohort subjects, 2415 individuals with newly diagnosed orbital wall fractures were identified. The overall incidence of orbital wall fractures was estimated as 46.19 (95% CI: 44.37–48.06) per 100,000 person-years. The incidence was high at 10–29 and 80+ years old and showed a male predominance with an average male-to-female ratio of 3.33. The most common type was isolated inferior orbital wall fracture (59.4%), followed by isolated medial orbital wall fracture (23.7%), combination fracture (15.0%), and naso-orbito-ethmoid fracture (1.5%). Of the fracture patients, 648 subjects (26.8%) underwent orbital wall fracture repair surgeries. Male sex, rural residence, and low income were associated with an increased risk of orbital wall fractures. Conclusions: The incidence of orbital wall fractures in Korea varied according to age groups and was positively associated with male sex, rural residency, and low economic income. The most common fracture type was an isolated inferior orbital wall fracture.