A decrease in macular microvascular perfusion after retinal detachment repair with silicone oil

AIM To observe whether silicone oil (SO) tamponade could decrease macular perfusion after retinal detachment repair. METHODS A prospective observational case-control study. Patients diagnosed with primary macular off rhegmatogenous retinal detachment undergoing successful retinal repair surgery with vitrectomy were strictly selected. Optical coherence tomography angiography findings were compared between SO and air tamponade groups. Two postoperative visiting points were set (1 and 3mo). RESULTS Totally 29 patients (29 eyes) were enrolled. Twenty cases had SO tamponade while 9 cases were with air tamponade. At the first visiting point, superficial parafoveal vessel density (PFSVD) significantly decreased in the SO group (P=0.0403), especially in the superior quadrant or superior-hemi area (P=0.0089, 0.0426, respectively). Parafoveal deep vessel density (PFDVD) had no difference between the two groups. At the second visiting point, all quadrants of PFSVD reduced significantly in the SO group (P=0.0256, 0.0001, 0.0031, <0.0001 in temporal, superior, nasal, and inferior area, respectively), but PFDVD remained no different. In the air group, all areas of PFSVD showed significantly improving from the first visit to the second one (P=0.0324, 0.0001, 0.0371, 0.0026, in temporal, superior, nasal, and inferior area, respectively); however, almost all quadrants of PFDVD showed no changes during this period. In the SO group, both PFSVD and PFDVD showed no obvious changes between the two visiting points. Besides, parafoveal full retinal thickness in the SO group reduced significantly at both visiting points over the air tamponade, while the foveal avascular zone area showed no difference in the two groups. CONCLUSION After retinal detachment surgery with vitrectomy and SO tamponade, superficial macular perfusion and full retinal thickness could decrease obviously when compared to air tamponade. This reduction process could persist throughout the tamponade period.