Fig. 3

Morphological characteristics of preoperative and postoperative IERM with different stages: A1: Preoperative OCTA image of stage 1 iERM shows: A distinct foveal pit is present; retinal layers are well-defined; a slight increase in curvature is observed in a small number of small vessels; A2-A3: Postoperative CMT is mildly elevated, with improved tortuosity of small vessels. A4: No Inner retinal dimpling appears postoperatively. B1: Preoperative OCTA image of stage 2 iERM shows: The fovea is absent; retinal layers are well-defined; multiple small vessels exhibit a wavy pattern; B2-B3: Postoperative CMT decreases, with reappearance of the fovea and reduced tortuosity of small vessels. B4: Severely Inner retinal dimpling appeared postoperatively. C1: Preoperative OCTA image of stage 3 iERM shows: The fovea is not visible; ectopic inner foveal layers are present, with identifiable retinal layers; small vessels are significantly deformed by the ERM; C2-C3: Postoperative CMT decreases significantly, with marked improvement in vessel deformation. C4: Severely Inner retinal dimpling appeared postoperatively. D1: Preoperative OCTA image of stage 4 iERM shows: The fovea is completely indistinguishable; Continuous ectopic inner foveal layers are present, with severely disordered retinal layers; coarse vessels are deformed towards to foveal center by the epiretinal membrane; D2-D3: Postoperative retinal thickness decreases remarkably, with identifiable retinal layers and nearly normal restoration of vessel morphology. D4: moderate Inner retinal dimpling appears postoperatively. The red box marked the same position before and after the operation, showing that the preoperative vascular tortuosity was significantly improved after surgery