The effect of epiretinal membrane surgery on macular microvasculature: an optical coherence tomography angiography study.

Purpose: To investigate both the possible effects of both idiopathic epiretinal membrane (IERM) itself and surgery on macular microvascular structure using optical coherence tomography angiography (OCT-A) and to determine the associations with structural and visual outcomes.

Methods: Twenty-four eyes of 24 patients with IERM and 24 eyes of 12 healthy controls were included. Vascular parameters, including the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were evaluated by OCT-A prior to and 6 months after ERM removal. The foveal avascular zone (FAZ, mm) area, parafoveal vascular density (VD, %) and flow area (mm) measurements were used to evaluate the macular vascular integrity.

Results: The mean preoperative vascular density (VD) of both plexuses was lower in eyes with IERM than in healthy eyes (both p = 0.0001). The mean preoperative flow area of the DCP in eyes with IERM was significantly lower than that in the control eyes (p = 0.016). There was no significant difference in the VD or flow area in either superficial or deep capillary plexuses as a result of surgery (SCP; p = 0.957, p = 0.97, DCP; p = 0.861, p = 0.6, respectively). Both the parafoveal DCP-VD and flow area in DCP were negatively correlated with best-corrected visual acuity (logMAR) at 6 months postoperatively (r = -0.46, p = 0.03; r = -0.52, p = 0.01, respectively).

Conclusion: Epiretinal membranes may cause dynamic microvascular changes at the macula. However, the effect of surgery on microvasculature may be more limited than that on anatomical and visual recovery. OCT-A may serve as a useful tool in understanding the pathophysiological basis of diseases.