Peripapillary microvasculature changes after vitrectomy in epiretinal membrane via swept-source OCT angiography

PURPOSE: To evaluate the peripapillary microvasculature changes in patients with epiretinal membrane (ERM) following pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling using swept-source optical coherence tomography angiography (SS-OCTA). METHOD: Medical records and multimodal imaging data of 33 eyes after PPV for ERM were retrospectively reviewed. Peripapillary SS-OCTA images of 6×6 mm(2) were recorded at at pre- and post-operatively every 6 months for 1 year. A semi-automated method was used to analyzed SS-OCTA images, excluding the optic disc area, using the MATLAB software. The peripapillary vessel density (pVD) of superficial capillary plexus (SCP) and deep capillary plexus (DCP) was quantified in four quadrants (superior, inferior, nasal and temporal). RESULT: The mean pVD in SCP and DCP decreased at 6- and 12-months follow-up. In sectoral analysis, superior, inferior, and temporal quadrants pVD in SCP and DCP were significantly reduced at 1 year after vitrectomy (all p < 0.05). Meanwhile, inferior quadrants pVD in SCP and DCP showed the earliest significant reduction at 6-months (p = 0.022 and 0.048, respectively). A reduction of post-operative mean pVD in DCP was significantly greater in patients with diabetic retinopathy (p = 0.043). CONCLUSION: Peripapillary capillary density significantly decreased after surgical removal of ERM. Vitrectomy with ILM peeling can cause peripapillary microvascular damage starting in inferior sector.