Aims To investigate macular vascular integrity using optical coherence tomography angiography (OCTA) in patients undergoing vitrectomy for idiopathic epiretinal membrane (ERM) removal and to determine its association with structural and visual outcomes.

Methods Forty-three patients with unilateral ERM who were followed for ≥6 months after surgery were included. Ophthalmological evaluations included best-corrected visual acuity (BCVA) and spectral-domain OCT (SD-OCT) before surgery and 6 months after surgery. We obtained en face OCTA images of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) for both eyes 6 months after ERM removal. We compared eyes with ERM to unaffected fellow eyes as controls and used interocular differences in the analyses.

Results Compared with the fellow eyes, eyes with ERM after surgery had a lower parafoveal vascular density (VD) and a smaller foveal avascular zone (FAZ) area in both SCP and DCP (all p<0.001). Interocular differences in the FAZ area and parafoveal VD were correlated with preoperative and postoperative central foveal thicknesses (all p<0.05). In addition, interocular differences in macular vascular integrity had a tendency to be correlated with SD-OCT parameters of the inner retinal layers. Finally, greater interocular differences in the FAZ area and parafoveal VD of both plexuses were significantly associated with worse postoperative BCVAs (all p<0.05).

Conclusions Assessing macular capillary plexuses via OCTA may be useful to quantify structural changes of the inner retinal layer and predict visual function in patients undergoing ERM removal surgery.