title: Does the presence of an epiretinal membrane alter the cleavage plane during internal limiting membrane peeling?
abstract: OBJECTIVE
  To determine whether the presence of a clinically and/or microscopically detectable epiretinal membrane (ERM) alters the cleavage plane during internal limiting membrane (ILM) peeling.
  
  
  METHODS
  Retrospective, observational, immunohistochemical study of ILM specimens using archival formalin-fixed, paraffin-embedded tissue.
  
  
  METHODS
  Fifty-one patients who had had ILM excision.
  
  
  METHODS
  Fifty-one ILM specimens peeled during vitrectomy for various etiologies were examined by light microscopy. The removal of ILM was assisted using Trypan blue (n = 30), indocyanine green (n = 7), or brilliant blue G (n = 14). Monoclonal antibodies to glial fibrillary acidic protein and to neurofilament protein were used to detect glial or neuronal cells respectively on the vitreous or retinal surfaces of the ILM. Specimens were divided into 2 groups: ILM peeled for full-thickness macular hole (MH; n = 31) and ILM peeled after removal of clinically detectable ERM (n = 20).
  
  
  METHODS
  Primary outcome measure was the localization of immunohistochemical markers to neuronal or glial cells on the vitreous or retinal surfaces of ILM. The secondary outcome measure was the correlation of the results of the primary measure with the dyes used to facilitate ILM peeling.
  
  
  RESULTS
  Glial and/or neuronal cells were detected on the retinal surface of the ILM in 10 of 31 (32%) of the MH ILM specimens and in 13 of 20 (65%) of the ILM peeled after ERM excision; the difference was significant (P = 0.02). There was no association between the presence of neuronal and glial cells with the type of dye used (P = 0.2). Of the 23 ILM specimens with cells attached to the retinal surface, 21 (91%) were associated with clinical and/or histologic evidence of ERM and 2 (9%) were not. The correlation between the presence of cells on the vitreous and the retinal surfaces of ILM was high (P<0.0001).
  
  
  CONCLUSIONS
  The findings suggest that ERM may be associated with sub-ILM changes that alter the plane of separation during ILM peeling. This study does not confirm any influence of dyes on the cleavage plane during surgery.
authors.affiliation: St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom. nkenawy@nhs.net
authors.forename: Nihal
authors.initials: N
authors.lastname: Kenawy
authors.forename: David
authors.initials: D
authors.lastname: Wong
authors.forename: Theodore
authors.initials: T
authors.lastname: Stappler
authors.forename: Mario R
authors.initials: MR
authors.lastname: Romano
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Das
authors.forename: Gillian
authors.initials: G
authors.lastname: Hebbar
authors.forename: Wendy
authors.initials: W
authors.lastname: Prime
authors.forename: Heinrich
authors.initials: H
authors.lastname: Heimann
authors.forename: Syed K
authors.initials: SK
authors.lastname: Gibran
authors.forename: Carl M
authors.initials: CM
authors.lastname: Sheridan
authors.forename: Yin Him
authors.initials: YH
authors.lastname: Cheung
authors.forename: Paul S
authors.initials: PS
authors.lastname: Hiscott
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001485:Basement Membrane / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D001557:Benzenesulfonates; D004396:Coloring Agents; D019773:Epiretinal Membrane / Q000175:diagnosis*; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D007208:Indocyanine Green; D008297:Male; D008875:Middle Aged; D016900:Neurofilament Proteins / Q000378:metabolism; D009457:Neuroglia / Q000473:pathology; D009474:Neurons / Q000473:pathology; D012164:Retinal Diseases / Q000601:surgery; D012189:Retrospective Studies; D014343:Trypan Blue; D014821:Vitrectomy
chemical_list: D001557:Benzenesulfonates; D004396:Coloring Agents; D005904:Glial Fibrillary Acidic Protein; D016900:Neurofilament Proteins; C006796:brilliant blue; D014343:Trypan Blue; D007208:Indocyanine Green