TO DRAIN OR NOT TO DRAIN? THE MANCHESTER BUCKLE STUDY

To assess whether external drainage of subretinal fluid (SRF) improves anatomical or visual outcomes in scleral buckle surgery for rhegmatogenous retinal detachment (RRD).

Retrospective review of 609 primary scleral buckles performed at Manchester Royal Eye Hospital (2008-2023). Pre/intraoperative characteristics, drainage use, best-corrected visual acuity (BCVA), and single-surgery anatomical success were analyzed.

Four hundred twenty-eight patients without SRF drainage and 181 with drainage were included. Groups were similar for age ( P = 0.33), preoperative BCVA ( P = 0.47), RRD type (dialysis vs. retinal hole, P = 0.17), high myopia ( P = 0.52), and trauma ( P = 0.06). Drainage group had more macula-off RRDs (48% vs. 39%, P = 0.05) and were more often operated on by consultants ( P < 0.01). Single-surgery anatomical success rates were 86.7% with drainage and 83.6% without ( P = 0.67). Final BCVA also showed no difference in all ( P = 0.47), macula-on ( P = 1.00), and macula-off eyes ( P = 0.17). After adjusting for age, high myopia, trauma, type of RRD, macula status, and surgeon grade, external SRF drainage was not independently associated with either single-surgery anatomical success (OR = 1.39, 95% confidence interval 0.81 to 2.36, P = 0.23) or postoperative BCVA (B = -0.023, 95% confidence interval -0.093 to 0.048, P = 0.532). Drainage caused subretinal hemorrhage in 34 eyes (18.8%), almost all (32) small and localized to the drainage site; no endophthalmitis, retinal incarceration, or vitreous loss occurred.

External SRF drainage during scleral buckling is safe but did not improve single-surgery anatomical success or BCVA. Its use should remain individualized based on RRD characteristics and surgeon preference.