Analysis of OCT angiography of macular epiretinal membrane after vitrectomy

Objective To analyze the changes of macular capillaries in patients with idiopathic macular epiretinal membrane (IMEM) after vitrectomy. Methods A retrospective study. The clinical data of 33 eyes of 33 cases with IMEM after vitrectomy and internal limiting membrane peeling from May 2015 to Jul. 2017 in Tianjin Eye Hospital were collected. All patients were diagnosed with optical coherence tomography angiography (OCTA) and followed-up for 12 months. Results The BCVA (logMAR) after surgery was improved from 0.700±0.309 to 0.252±0.182 (t=7.212, P=0.000), while central macular thickness (CMT) was decreased from (447.44±96.96)μm to (373.56±82.36) μm after surgery (t=8.247, P=0.000), and foveal avascular zone (FAZ) was increased from (0.120±0.059)mm2 to (0.145±0.063)mm2 (t=6.660, P=0.000). The macular vascular density (MVD) in the superficial and deep macular area examined with OCTA were increased significantly (P<0.05). There was a negative correlation between BCVA and CMT (r=-0.507, P=0.014), while a positive correlation between BCVA and deep MVD (r=0.578, P=0.024). Conclusion Microvascular changes in macular area are quantitatively detected with OCTA, and FAZ and MVD increase in patients after IMEM vitrectomy. Key words: Membrane, epiretinal, macular; Vitrectomy; Injuries, microvessls; Tomography, vascular, optical coherence