title: [A porous coral-like structure - a new insight into the morphology of the inner limiting membrane of the retina?]
abstract: To date, the internal limiting membrane (ILM), specifically, the side facing the retina, has never been studied by two parallel, mutually complementary methods. This is an attempt to explain favorable results of ILM peeling in various macular pathologies.
  
  
  OBJECTIVE
  By employing scanning (SEM) and transmission electron microscopy (TEM), to identify morphological features of epiretinal samples removed during vitrectomy in patients with lamellar macular hole (LMH) or epiretinal membrane (ERM).
  
  
  METHODS
  We studied 23 eyes of 23 patients divided into two groups. The first group (13 samples, 11 eyes) consisted of patients with LMH; the second (12 samples, 12 eyes) - with ERM. The surgeries yielded a total of 21 epiretinal samples peeled simultaneously with the ILM and 4 epiretinal samples (2 eyes) peeled in two parts, the second part containing the ILM. One half of the samples was studied by SEM without prior dehydratation, the other - by TEM.
  
  
  RESULTS
  The study revealed a high degree of ultrastructural similarity between the two groups of ILM samples. Judging from SEM findings, two sides of the membrane were clearly identified. Porous coral-like structures (PCS) were discovered on the side facing the retina. TEM in the area of PCS discovered parallel arrangement of multiple Muller cell (MC) bodies and processes separated by wide layers of the intercellular matrix. The vitreal side of all ILM samples was notable for numerous fibroblast-like cells. Many variously shaped petrified structures were found on both sides of the membrane.
  
  
  CONCLUSIONS
  During the so called ILM peeling, the surgeon removes a layered structure that includes the basal membrane of MC, cells and fibers attached to its vitreal side, and one more layer comprised by PCS and rather readily torn off from the main massif. The functional significance of this previously unknown structure as well as the effect of its partial removal during surgical manipulations with neurosensory retina in the macular region is yet to be investigated.
authors.affiliation: Posterior segment eye surgery and diagnostics center LLC, 2-aya Vladimirskaya St., Moscow, 111123, Russian Federation.
authors.forename: G E
authors.initials: GE
authors.lastname: Stolyarenko
authors.affiliation: Posterior segment eye surgery and diagnostics center LLC, 2-aya Vladimirskaya St., Moscow, 111123, Russian Federation.
authors.forename: A A
authors.initials: AA
authors.lastname: Kolchin
authors.affiliation: N.F. Gamaleya Federal Research Center for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 18 Gamalei St., Moscow, 123098, Russian Federation.
authors.forename: L V
authors.initials: LV
authors.lastname: Didenko
authors.affiliation: N.F. Gamaleya Federal Research Center for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 18 Gamalei St., Moscow, 123098, Russian Federation.
authors.forename: T G
authors.initials: TG
authors.lastname: Borovaya
authors.affiliation: N.F. Gamaleya Federal Research Center for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 18 Gamalei St., Moscow, 123098, Russian Federation.
authors.forename: N V
authors.initials: NV
authors.lastname: Shevlyagina
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012160:Retina / Q000000981:diagnostic imaging / Q000473:pathology / Q000648:ultrastructure; D012167:Retinal Perforations / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D014821:Vitrectomy / Q000379:methods; D057586:Vitreoretinal Surgery / Q000379:methods