Complications of preseptal versus retroseptal transconjunctival approach for isolated orbital floor fracture repair: A double-blind, non-inferiority, randomized, split-face controlled trial

•Question: Are transconjunctival approach (TCA) variants for isolated orbital floor fractures (OFF) repair non-inferior to each other?.•Finding: In this randomized, split-face controlled trial with 193 participants, both preseptal (PS-TCA) and postseptal (RS-TCA) TCA variants for isolated OFF repair showed comparable outcomes, although RS-TCA presented slightly higher complication risks.•Meaning: Surgeons can use both PS-TCA and RS-TCA for isolated OFF repair with no significant difference in favorable outcomes and potential postoperative complications. Effective surgical access to the orbital floor facilitates surgery and mitigates postoperative complications (PC). The aim of this study was to compare PC between the preseptal and retroseptal transconjunctival approaches (PS-TCA/RS-TCA) for isolated orbital floor fracture (OFF). Using a double-blind, non-inferiority, randomized, split-face study design, patients aged ≥ 18 years with bilateral isolated OFF were enrolled. A sample size of 177 eyes per group was determined through power analysis. The primary predictor variable was the surgical approach, and the main outcome was the PC rate at month 6. Statistical analyses were computed with a significance level at 0.05 and the non-inferiority margin at a relative risk (RR) of 0.045. The final sample included 193 patients (23.3 % female; age, 42.8 ± 18.1 years). Both TCA variants exhibited comparable PC rates (5.2 % for PS-TCA vs. 7.3 % for RS-TCA; P = 0.53; absolute risk, +2.07 % [95 % CI, -2.74 % to 6.89 %]; RR, 1.4 [95 % CI, 0.64 to 3.07]). Approximately one in every 49 patients experiencing PC with RS-TCA (number needed to harm, 48.3). Both TCA methods can be used without different PC rates at 6 months postoperatively. Future research should focus on TCA in combination with other surgical approaches for multiple orbital wall reconstruction.