Adjunctive dexamethasone implant during vitrectomy with silicone oil for diabetic tractional retinal detachment: a systematic review and exploratory meta-analysis.

Abstract

Background: Diabetic tractional retinal detachment (TRD) secondary to proliferative diabetic retinopathy is a vision-threatening complication that may require pars plana vitrectomy in selected cases, particularly when the macula is threatened or detached. Silicone oil tamponade is commonly used in complex cases, although tamponade choice varies according to surgical findings and surgeon preference.

Objectives: To evaluate surgical outcomes associated with adjunctive dexamethasone implant during pars plana vitrectomy with silicone oil or heavy silicone oil tamponade for diabetic tractional retinal detachment.

Methods: A comprehensive literature search of PubMed, Scopus, Web of Science, and ClinicalTrials.gov was performed from inception through 2025. Randomized and non-randomized comparative studies assessing PPV with silicone oil with or without adjunctive dexamethasone implant were considered. Definitions of postoperative PVR and retinal redetachment were accepted as reported by the original studies; no individual-level imaging or independent photographic regrading was available. The anatomical outcome was an exploratory composite of study-reported postoperative proliferative vitreoretinopathy (PVR) and/or retinal redetachment outcomes. Because definitions and follow-up time points differed across studies, this outcome was not treated as a uniformly graded PVR endpoint. Randomized and non-randomized comparative studies were identified; randomized trials were prioritized for the main analysis, while the non-randomized study was considered separately because of serious risk of bias. Secondary outcomes included best-corrected visual acuity (BCVA), central subfield thickness (CST), ocular hypertension, and postoperative complications. The protocol was prospectively registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD420261283105) prior to the commencement of the review.

Results: Four studies involving 305 eyes were included. In the main randomized-trial analysis, two studies comprising 123 eyes contributed to the exploratory study-reported postoperative proliferative/redetachment composite. The pooled estimate was highly imprecise (RR 0.20, 95% CI 0.00 to 16.06; I² = 0%) and did not provide conclusive evidence of benefit. In an exploratory sensitivity analysis including the non-randomized study, the estimate favored dexamethasone implant, but this analysis was subject to serious risk of bias. BCVA and CST findings were limited by small sample sizes, heterogeneity, and inconsistent reporting. Intraocular-pressure outcomes were not pooled because definitions and assessment time points differed across studies.

Conclusion: Current evidence is insufficient to support routine adjunctive dexamethasone implant use during vitrectomy with silicone oil for diabetic tractional retinal detachment. The available studies provide only a hypothesis-generating signal of fewer study-reported postoperative proliferative or redetachment events. Use should remain selective and individualized until adequately powered randomized trials with standardized anatomical outcomes are available.

Clinical trials number: Not applicable.