Comparisons of Clinical and Functional Characteristics of Patients with Epiretinal Membrane, Macular Pseudohole, Epiretinal Membrane Foveoschisis, and Lamellar Macular Hole

<b>Background/Objectives:</b> To investigate and compare the clinical characteristics of epiretinal membrane (ERM) and associated diseases: macular pseudohole (MPH), ERM foveoschisis (ERM-FS), and lamellar macular hole (LMH). <b>Methods:</b> We retrospectively reviewed of all patients who underwent vitrectomy with at least 6 months follow-up, all eyes were classified into four groups: ERM, MPH, ERM-FS, and LMH. Age, gender, presence of glaucoma, preoperative spherical equivalent, axial length (AL), preoperative and postoperative best-corrected visual acuity (BCVA), metamorphopsia using M-CHARTS^®, and frequency of overlapping associated diseases were investigated. The association between pre- and postoperative BCVA and these clinical factors was analyzed. <b>Results:</b> After enrolling 718 eyes of 662 patients, eyes were classified as ERM (592 eyes), MPH (76 eyes), ERM-FS (63 eyes), and LMH (42 eyes). Overlapping cases included MPH+ERM-FS (17 eyes), ERM-FS+LMH (14 eyes), MPH+LMH (18 eyes), and MPH+ERM-FS+LMH (3 eyes). The AL was significantly longer (<i>p</i> < 0.05) in MPH, ERM-FS, and LMH versus ERM. In all groups, BCVA significantly improved after vitrectomy. Although preoperative BCVA was not significantly different among the four groups, postoperative BCVA was significantly worse for LMH versus ERM (<i>p</i> < 0.001). Preoperative metamorphopsia was significantly more severe in ERM (0.52 ± 0.51) versus MPH (0.34 ± 0.29) (<i>p</i> < 0.05). Postoperative BCVA correlated with preoperative BCVA and age in all groups except LMH. <b>Conclusions:</b> Associated diseases often overlap and were more myopic than ERM. Postoperative BCVA was worse in LMH, while preoperative metamorphopsia was severe in ERM. These results highlight the importance of both clinical and functional evaluations in determining surgical indications and predicting visual outcomes.