Endothelial cell loss post-pars plana vitrectomy with silicone oil tamponade: a comparative study of rhegmatogenous and tractional retinal detachments

Purpose: To compare the rate of endothelial cell density (ECD) loss in patients undergoing pars plana vitrectomy (PPV) with silicone oil (SO) tamponade, focusing on differences between rhegmatogenous retinal detachment (RRD) and tractional retinal detachment (TRD) cases. Methods: A retrospective analysis was conducted on 427 eyes from patients with RRD (n=293) and TRD (n=134) who underwent PPV with SO tamponade. ECD changes were recorded, and the impact of factors such as age, gender, surgical technique, SO emulsification, tamponade duration, and postoperative intraocular pressure (IOP) were evaluated using univariate and multivariate regression models. Results: TRD patients showed a significantly higher ECD loss (9.17%) compared to RRD patients (3.39%). ECD loss was particularly severe in patients undergoing combined anterior and posterior surgeries, as the vitrectomy in combination with phacoemulsification (VCP) group showed a loss of 6.85% and the intraocular lens (IOL) group exhibited 6.48%. Multivariate regression revealed a 1% increase in ECD loss for every 8-year increase in age (P=0.006). No significant correlation between transient high intraocular pressure (THIOP) and ECD loss. Conclusion: TRD patients are at greater risk of ECD loss following PPV with SO tamponade, particularly in cases involving combined surgeries. Advanced age and the absence of a natural lens were associated with greater ECD loss. Maintaining postoperative intraocular pressure (IOP) below 40 mmHg is considered safe for ECD.Further investigation into the mechanisms of SO-related endothelial damage is needed.