The Incidence of Strabismus After Upper and Lower Blepharoplasty in the United States.

PURPOSE:To compare the incidence of strabismus after upper and lower blepharoplasty in the United States. METHODS:Retrospective cohort study of adults (age ≥18 years) in the IRIS Registry (Intelligent Research in Sight) who underwent blepharoplasty between January 1, 2013 and December 31, 2020. The primary outcome was the Kaplan-Meier estimated cumulative incidence of strabismus diagnosis and surgery within 3 years of blepharoplasty. Multivariable Cox regression was used to determine the association of blepharoplasty type with strabismus diagnosis and surgery, adjusting for patient age, sex, and geographic region. RESULTS:Blepharoplasty was performed in 368,623 patients (median [interquartile range] age, 69 [63-75] years, and 69% female). Compared with those undergoing upper eyelid blepharoplasty, patients treated with lower eyelid blepharoplasty were slightly younger (median age, 66 vs. 69 years; p < 0.001) and more likely to be female (71% vs. 69%; p < 0.001). There was a greater 3-year incidence of strabismus diagnosis (2.0% vs. 1.5%; p < 0.001) and a greater 3-year incidence of strabismus surgery (0.15% vs. 0.06%; p = 0.003) for individuals undergoing lower vs. upper blepharoplasty. After adjusting for age, sex, and geographic region, lower blepharoplasty was associated with a higher 3-year risk of strabismus diagnosis (HR, 1.49; 95% CI, 1.23-1.81; p < 0.001) and surgery (HR, 2.53; 95% CI, 1.27-5.03; p = 0.008). CONCLUSIONS:This registry-based analysis found that individuals undergoing lower eyelid blepharoplasty were at higher risk of strabismus compared with those undergoing upper eyelid blepharoplasty. Using large databases to understand the incidence of complications of frequently performed procedures may improve ophthalmologists' ability to provide data-driven counseling on surgical risks prior to intervention.