Early vascular changes after silicone oil removal using optical coherence tomography angiography.

Background: This study evaluated the vascular changes in the macular and peripapillary regions before and after silicone oil (SO) removal in patients with rhegmatogenous retinal detachment.

Methods: This single-center case series assessed patients who underwent SO removal at one hospital. Patients who underwent pars plana vitrectomy and perfluoropropane gas tamponade (PPV + CF) were selected as controls. Superficial vessel density (SVD) and superficial perfusion density (SPD) in the macular and peripapillary regions were assessed by optical coherence tomography angiography (OCTA). Best-corrected visual acuity (BCVA) was assessed using LogMAR.

Results: Fifty eyes were administered SO tamponade, 54 SO tamponade(SOT) contralateral eyes, 29 PPV + CF eyes, and 27 PPV + CF contralateral eyes were selected. SVD and SPD in the macular region were lower in eyes administered SO tamponade compared with SOT contralateral eyes (P < 0.01). Except for the central area, SVD and SPD in the other areas of the peripapillary region were reduced after SO tamponade without SO removal (P < 0.01). No significant differences were found in SVD and SPD between PPV + CF contralateral and PPV + CF eyes. After SO removal, macular SVD and SPD showed significant improvements compared with preoperative values, but no improvements in SVD and SPD were observed in the peripapillary region. BCVA (LogMAR) decreased post-operation and was negatively correlated with macular SVD and SPD.

Conclusions: SVD and SPD are decreased during SO tamponade and increased in the macular region of eyes that underwent SO removal, suggesting a possible mechanism for reduced visual acuity during or after SO tamponade.

Trial Registration: Registration date: 22/05/2019; Registration number, ChiCTR1900023322; Registration site, Chinese Clinical Trial Registry (ChiCTR).