Heavy silicone oil tamponade in retinal detachment surgery: A systematic review and single-arm meta-analysis on Densiron 68 and Oxane HD

Abstract

PurposeHeavy silicone oils (HSOs) have been introduced in rhegmatogenous retinal detachment (RRD) surgery to support inferior/posterior breaks and proliferative vitreoretinopathy (PVR). This meta-analysis assessed the results and adverse effects of two widespread HSOs in RRD surgery. DesignSystematic review and meta-analysis. MethodsThe study was conducted in accordance with PRISMA guidelines and registered on PROSPERO. We retrieved randomized controlled trials, prospective, retrospective and cross-sectional studies discussing the treatment of RRD with HSO injection (Densiron 68 or Oxane HD), published from 2000 to nowadays, conducting a computer-based search of the following databases: PubMed/Medline, Embase, Cochrane, Google Scholar and Web of Science. This meta-analysis focused on primary success rates, visual acuity (VA) improvement and postoperative complications. ResultsA total of 16 retrospective/prospective cohort studies on 723 eyes (506 with Densiron 68 and 217 with Oxane HD tamponade), divided into 345 primary and 378 recurrent RRDs were included. Following GRADE scale, 11 studies had a “moderate” and 5 a “low” evidence level. Mean duration of HSO tamponade ranged from 7.2 weeks to 15.3 months, but generally lasting 3–6 months. Pooled primary success rate was 79% (95%CI: 72 to 86%), being 85% (95%CI: 78 to 91%) in Oxane studies and 76% (95%CI: 66 to 87%) in Densiron studies. After HSO removal, recurrences of RRD were 6–50%, highest in studies with greater baseline recurrent RRD. Pooled VA improvement was 0.47 LogMAR (95%CI: 0.29 to 0.65). Studies with Oxane showed average VA improvement of 0.31 LogMAR (95%CI: -0.18 to 0.80), while VA improvement was 0.47 LogMAR (95%CI: 0.33 to 0.75) in Densiron studies. Differently from Oxane studies, all the 9 studies in the Densiron 68 subgroup reported final mean VA improvement. Even if affected by great heterogeneity, the major adverse effects were anterior chamber inflammation (pooled average 20%, 95%CI: 13 to 26%), HSO emulsification (pooled average 16%, 95%CI: 10 to 21%) and IOP elevation (pooled average 22%, 95%CI: 16 to 27%). ConclusionHSO offers good anatomical outcomes in complex RRD cases, while visual outcomes, although improving, are significantly hampered by poor baseline condition. Inflammation, emulsification and raise of IOP are well-known postoperative adverse effects.