PurposeTo discuss the unique morphology and origin of epiretinal proliferation associated with macular hole (EPMH) occasionally observed in full-thickness macular hole (FT-MH) or lamellar hole (LH) and to introduce the perifoveal crown phenomenon encountered when removing this unusual proliferative tissue.MethodsSixteen patients showing EPMH in spectral domain-optical coherence tomography were selected from 212 patients diagnosed with MH, LH, FT-MH, impending MH, macular pseudohole, or epiretinal membrane between January 2013 and December 2014. Of the 212 patients included for clinical analysis, 33, 23, 11, 7, and 190 exhibited LH, FT-MH, impending MH, macular pseudohole, and epiretinal membrane, respectively. We reviewed visual acuity, macular morphology, and clinical course. Surgical specimens were analyzed histologically.ResultsEPMH presented as an amorphous proliferation starting from the defective inner/outer segment (IS/OS) junction covering the inner macula surface. Among the 16 patients with EPMH, 11 underwent vitrectomy, and all exhibited the intraoperative perifoveal crown phenomenon. EPMH tissue was sampled in three patients, one of whom had more tissue removed than intended and showed delayed recovery in visual acuity. Despite hole closure, IS/OS junction integrity was not successfully restored in four of 11 patients. Five patients were followed-up without surgical intervention. Visual acuity slightly decreased in three patients and did not change in one patient, while the remaining patient was lost during follow-up. Among the three perifoveal crown tissues obtained, two were successfully analyzed histologically. Neither tissue showed positivity to synaptophysin or S-100 protein, but one showed positivity to cytokeratin protein immunohistochemical staining.ConclusionsEPMH exhibited a distinct but common configuration in spectral domain-optical coherence tomography. An epithelial proliferation origin is plausible based on its configuration and histological analysis. Perifoveal crown phenomenon was observed when removing EPMH during vitrectomy.

Purpose To determine the origin of epiretinal proliferation (EP), a condition that is occasionally observed in lamellar hole and macular hole cases, and EP outcomes after vitrectomy. Methods This is a retrospective observational case review of 17 eyes with EP that underwent vitrectomy, EP dissection, and internal limiting membrane peeling between January 2013 and December 2016. Surgical specimens of EP tissue were successfully obtained from 5 cases and they were analyzed after immunohistochemical staining. Postoperative outcomes, including best-corrected visual acuity (BCVA) and macular configuration in spectral domain-optical coherence tomography, were reviewed. Results Mean BCVA improved from 0.54 ± 0.36 logarithms of the minimum angle of resolution preoperatively to 0.32 ± 0.38 logarithms of the minimum angle of resolution postoperatively ( p = 0.002). BCVA improved in 13 eyes and remained unchanged in four eyes. No cases experienced vision decline after surgery. All 17 patients' lamellar hole or macular hole were successfully closed. Despite hole closure, ellipsoid zone defects were not corrected in 11 of the 17 patients. In immunohistochemical analyses, anti-glial fibrillary acidic protein and pan-keratin (AE1/AE3) were positive, but synaptophysin, anti-α-smooth muscle actin, and anti-CD68 were negative. Conclusions The epiretinal proliferative membrane seems to originate from Müller cells, not from the vitreous. It is unclear whether retinal pigment epithelia also contribute to EP formation. Gentle handling and preservation of the epiretinal proliferative tissue is crucial for successful surgical outcomes.