title: Epiretinal Proliferation Associated with Macular Hole and Intraoperative Perifoveal Crown Phenomenon.
abstract: OBJECTIVE
  To 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.
  
  
  METHODS
  Sixteen 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.
  
  
  RESULTS
  EPMH 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.
  
  
  CONCLUSIONS
  EPMH 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.
authors.affiliation: Department of Ophthalmology, HanGil Eye Hospital, Incheon, Korea.
authors.forename: Gisung
authors.initials: G
authors.lastname: Son
authors.affiliation: Department of Pathology, Chonnam National University Hwasun Hospital, Hwasun, Korea.
authors.forename: Ji Shin
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, HanGil Eye Hospital, Incheon, Korea.
authors.forename: Suchan
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, HanGil Eye Hospital, Incheon, Korea.
authors.forename: Joonhong
authors.initials: J
authors.lastname: Sohn
mesh_terms: D000368:Aged; D019773:Epiretinal Membrane / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D005584:Fovea Centralis / Q000000981:diagnostic imaging*; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D012167:Retinal Perforations / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D014792:Visual Acuity; D014821:Vitrectomy
keywords: Epiretinal proliferation; Lamellar hole; Macular hole; Perifoveal crown phenomenon; Retinal pigment epithelium