Anatomical and Functional Outcomes of Inferior Versus Non-Inferior Giant Retinal Tear-Related Retinal Detachment: The Manchester GRT Study.

PURPOSE: To compare anatomical and visual outcomes of inferior versus non-inferior giant retinal tear related rhegmatogenous retinal detachment (GRT-RRD) after primary pars plana vitrectomy (PPV). METHODS: This retrospective single-centre study included 110 eyes undergoing primary PPV for GRT-RRD between 2012 and 2024. Inferior GRTs were defined as GRTs crossing the 5-7 o'clock meridians. Outcomes included single-surgery anatomical success (SSAS), final anatomical success (FAS), postoperative PVR grade C, and best-corrected visual acuity (BCVA). Propensity score matching with double-robust regression and G-computation was used to adjust for baseline confounders. RESULTS: Of 110 eyes, 63 (57.3%) had inferior GRT-RRDs. Inferior GRT-RRDs occurred in younger patients (47 vs 54 years, p=0.01) and were more extensive (6.0 vs 4.5 clock-hours, p=0.027). SSAS (93.5% vs 83.0%), FAS (95.7% vs 93.5%), postoperative PVR-C rates, and BCVA at 2 months and final follow-up were comparable between inferior and non-inferior groups on univariable analysis. After propensity score matching (PSM), inferior GRT crossing was associated with a lower risk of SSAS failure (risk difference -9.9%, p=0.027) in all eyes and with better final follow-up BCVA in macula-on eyes (mean difference -0.493 logMAR, p=0.001). Within inferior GRT-RRDs, gas and silicone oil tamponade achieved similar SSAS (97.4% vs 87.0%), but gas was associated with better final follow-up BCVA (median 0.21 logMAR (20/32) vs 0.55 logMAR (20/70); p<0.001). CONCLUSION: After PSM, inferior GRT-RRDs were associated with a lower risk of SSAS failure and better final follow-up BCVA in macula-on eyes. Gas tamponade achieved comparable anatomical outcomes and was associated with better final follow-up BCVA than silicone oil.