Epiretinal Proliferation Associated with Lamellar Hole or Macular Hole: Origin and Surgical Prognosis

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.