Background
Silicone oil (SO)-associated unexplained visual loss (UVL) is a serious phenomenon after pars-plana-vitrectomy (ppV). Due to reports of UVL, we started earlier SO removal (SOR) in macula-on rhegmatogenous retinal detachments (RRD) in 2020. This study aims to investigate the effect of a shorter (≤ 60 days) compared to a long-term (> 60 days) SO tamponade.
Methods
All consecutive macula-on RRDs (2020–2025) treated with ppV were retrospectively analysed comparing eyes with short-term vs. long-term SO tamponade regarding best corrected visual acuity (BCVA), intraocular pressure (IOP), central foveal thickness (CFT) and the incidence of UVL. Inclusion criteria were a detailed clinical documentation and a minimum follow-up (FU) of 2 months after SOR. If available, CFT values were analysed before, during, and after SO.
Results
Overall, 37 eyes received ppV with SO for macula-on RRD. In 25 eyes (68%), SOR was performed within 60 days. Due to organizational issues (Covid, capacity) or patient-related factors (cancellation, illness), SO remained for longer than 60 days in 12 eyes (32%). Primary reattachment was achieved in all eyes. In the short-term group SOR was after 36 days (SD 13.4) and in the long-term cohort after 92 days (SD 20.9). UVL (≥ 2 Snellen lines BCVA loss without correlate) was significantly more common in the long-term (5/12) than in the short-term SO group (0/25) (p = 0,002). There were no differences in intra -and postoperative parameters (cut-suture time, IOP, CFT). Eyes with long-term SO had a final BCVA of logMAR 0.5 (SD 0.34) compared to a preoperative BCVA of logMAR 0.3 (SD 0.21). In eyes with short-term SO the BCVA before surgery (0.3; SD 0.29) and after SOR (0.3; SD 0.28) were comparable. The final BCVA after SOR was significantly better after short-term than after long-term tamponade (p = 0.033).
Conclusion
Eyes with a shorter SO tamponade (≤ 60 days) had better postoperative BCVA, while 42% in the long-term group (> 60 days) experienced UVL Taking into account the limitations of our small cohort, the risk of UVL during SO tamponade should be considered, especially in macula-on cases. Currently, an early SOR is the only modifiable surgical approach to address this adverse event.