Comparison of fundus changes following silicone oil and sterilized air tamponade for macular-on retinal detachment patients

BACKGROUND: To investigate different tamponade effects of intravitreal silicone oil (SO) and sterilized air on macular vasculature and structure after successful retinal repair for macular-on rhegmatogenous retinal detachment (RRD) patients. METHOD: 21 eyes (21 patients) with macular-on RRD underwent single pars plana vitrectomy following intravitreal SO or sterilized air (Gas) tamponade. Optical Coherence Tomography (OCT) and angiography were used to evaluate retinal layer thickness and flow density (FD) changes throughout the observation period of 12 weeks. Retinal layers were segmented into 7 sets: NFL, GCL + IPL, INL, OPL, ONL + IS, OS+RPE and BRM. Macular perfusion system was segmented into superficial and deep capillary plexus flow density (SCPFD, DCPFD), and choriocapillaries plexus flow density (CCPFD). RESULT: Compared to Gas tamponade, SO tamponade led to more decrease in both superficial and deep retinal blood flow during observation. NFL thickness was found to decrease in both Gas tamponade and SO tamponade eyes. SO tamponade resulted in more pronounced decrease which led to significant intergroup difference. Opposite changing trends were found in GCL + IPL and ONL + IS thicknesses due to different means of tamponade. SO tamponade caused thicknesses of these two segmented layers to decrease, which led to significant intergroup differences. SO tamponade also led to more decrease in INL, OPL thicknesses. No significant intergroup difference of choroidal thickness was observed. CONCLUSION: Compared to gas, silicone oil could have more negative tamponade effects on both fundus vasculature and structure.