Association of retinal vessel density with retinal sensitivity in surgery for idiopathic epiretinal membrane

Purpose: The success of surgical treatment for idiopathic epiretinal membrane (ERM) is measured by postoperative best-corrected visual acuity (BCVA), metamorphopsia, and foveal retinal sensitivity (RS).This study searched for predictive biomarkers of surgical success by determining the association between foveal RS and various aspects of vessel density (VD) in the fovea of patients with ERM. Methods: The study examined 25 eyes of 25 patients with ERM who underwent 27-gauge microincision vitrectomy surgery (MIVS). RS was measured with microperimetry (MP-3; NIDEK) at four central points in the fovea with an interpoint distance of 2°. VD was measured with SD-OCT (RS 3000; NIDEK) within the 1-mm² square defined by the 4 RS points at various depths, including the superficial and deep retinal capillary plexus (SCP and DCP, respectively). Results: Though VD did not change throughout the follow-up period, BCVA and RS significantly improved 1 and 3 months after surgery, respectively (both P < 0.0017). Postoperative RS at 6 months was positively correlated with postoperative DCP VD at 1, 3, and 6 months (r = 0.62, P = 0.001; r = 0.40, P = 0.049; r = 0.53, P = 0.007, respectively), but not with SCP VD at any time point. Multiple regression analysis confirmed that postoperative RS at 6 months was associated with postoperative DCP VD at 1 month (P = 0.03). Conclusion: Higher postoperative DCP VD at 1 month contributed to better postoperative foveal RS at 6 months. Early postoperative VD in the fovea might be a useful predictive biomarker of late postoperative RS in the fovea in ERM patients.