Regional disparities in emergency retinal surgery: interregional transfer and visual disability in a nationwide...

To assess regional disparities in access to emergency surgery for rhegmatogenous retinal detachment (RRD) in South Korea and the association between interregional patient transfer and long-term visual disability.

We used the Health Insurance Review and Assessment Service database to identify 54,269 patients aged ≥11 years who underwent RRD surgery within 30 days of diagnosis during 2014-2023. Interregional transfer was defined as discordance between the regions of residence and surgery across 6 administrative regions. Logistic regression and Cox proportional hazards models were used to assess associations of transfer with reoperation and visual disability registration, adjusting for demographic characteristics, comorbidities, and socioeconomic factors.

Overall, 5,224 patients (9.6%) underwent interregional transfer; 76.4% traveled to the Seoul metropolitan area, the only net recipient region (+12.2%). Jeju (-38.6%) and Gangwon (-28.8%) had the greatest outflow. Transfer was associated with a higher risk of visual disability (adjusted hazard ratio, 1.4; 95% confidence interval: 1.2-1.7; P < 0.001), but not with reoperation (P = 0.960). Surgical delay was more frequent among transferred patients (42.0% vs 33.6%; P < 0.001). Jeju's net outflow decreased from -69.8% in 2018 to -2.6% in 2023.

Despite universal health insurance, regional disparities in access to retinal surgery persist in Korea, with services concentrated in the Seoul metropolitan area. Transfer was independently associated with visual disability but not reoperation. The underlying mechanism likely involves referral of complex cases, patient preference, and transfer-related delay, although claims data cannot distinguish their relative contributions. Jeju's rapid improvement in self-sufficiency illustrates the potential for targeted regional investment to reduce these disparities.