Silicone oil versus gas tamponade in vitrectomy for fovea-on proliferative diabetic retinopathy: visual, anatomical, and optical coherence tomography angiography changes

Purpose To compare the functional and anatomical outcomes of using silicone oil (SO) and perfluoropropane gas (C3F8) as tamponades following pars plana vitrectomy (PPV) for diabetic vitrectomy. Patients and methods Fovea-on patients scheduled for PPV, either due to diabetic tractional retinal detachment that threatens the fovea or fibrovascular membranes distorting the fovea, were included in the study. They were randomized to receive either SO or C3F8. Best corrected visual acuity (BCVA), retinal anatomical success, and retinal optical coherence tomography angiography were assessed throughout the 6-month study period. Results Thirty eyes (15 from each group) with similar baseline characteristics completed the study period and were analyzed. No statistically significant differences were observed between the two groups at the 6-month mark concerning the final BCVA, anatomical success, and optical coherence tomography angiography vascular density parameters. Twenty-three (76.6%) patients experienced stable or improved BCVA at 6 months, despite a significant overall decrease in superficial vascular plexus (SVP) and deep vascular plexus densities in both groups. There was an inverse correlation between preoperative parafoveal SVP density and the change in logMAR BCVA during the study period ( P =0.016). Conclusion There were no functional or anatomical differences observed between using SO or C3F8 as tamponading agents following PPV in eyes with fovea-on diabetic tractional retinal detachment or fibrovascular membranes distorting the fovea. Preoperative parafoveal SVP density may serve as a useful prognostic visual indicator in these patients.