title: Pathologically reduced subbasal nerve density in epithelial basement membrane dystrophy is unaltered by phototherapeutic keratectomy treatment.
abstract: OBJECTIVE
  To investigate the effect of phototherapeutic keratectomy (PTK) treatment on corneal epithelial wing cell and corneal subbasal nerve density in epithelial basement membrane dystrophy (EBMD).
  
  
  METHODS
  A total of 39 patients with EBMD who underwent PTK treatment, 40 healthy volunteers, and 24 untreated eyes with EBMD were examined with laser-scanning in vivo confocal microscopy (IVCM). Corneal subbasal nerves and epithelial wing cells were manually quantified from IVCM images by two observers, while epithelial wing cells were additionally quantified by a fully automated method.
  
  
  RESULTS
  Subbasal nerve density was significantly reduced in untreated (10,164 ± 4139 μm/mm(2); n = 24) and PTK-treated (10,624 ± 4479 μm/mm(2); n = 39) EBMD eyes, relative to healthy controls (18,241 ± 4479 μm/mm(2); n = 40) (P < 0.001). Subbasal nerve density in PTK-treated and untreated eyes did not differ (P > 0.05). Epithelial wing cell density did not differ between PTK-treated and untreated EBMD eyes, by either manual or automated analysis; however, epithelial wing cell density in PTK-treated EBMD corneas was significantly reduced (P = 0.008) relative to healthy corneas, by automated cell counting.
  
  
  CONCLUSIONS
  Subbasal nerve density in EBMD is reduced by 45% and recovers only to the reduced level in the long term after PTK treatment, whereas epithelial wing cell density in EBMD is not affected by PTK in the long term. Fully automated cell analysis from IVCM images could provide an objective, standardized means to quantify and compare corneal cell densities in future studies.
authors.affiliation: Department of Clinical and Experimental Medicine-Ophthalmology, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Germundsson
authors.forename: Neil
authors.initials: N
authors.lastname: Lagali
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050541:Bowman Membrane / Q000294:innervation / Q000473:pathology* / Q000601:surgery; D002452:Cell Count; D003316:Corneal Diseases / Q000473:pathology / Q000601:surgery*; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009882:Ophthalmic Nerve / Q000473:pathology*; D018903:Photorefractive Keratectomy / Q000379:methods*; D012189:Retrospective Studies; D055815:Young Adult
keywords: epithelial basement membrane dystrophy; epithelial wing cell; phototherapeutic keratectomy; subbasal nerves