title: Subbasal nerve regeneration after LASEK measured by confocal microscopy.
abstract: OBJECTIVE
  To determine the relationship between the degree of subbasal nerve regeneration and corneal sensation and tear film functions after LASEK using corneal confocal microscopy.
  
  
  METHODS
  This prospective, observational, and longitudinal study included 35 LASEK patients who underwent tear breakup time assessment, phenol red thread test, corneal esthesiometry, and confocal microscopy preoperatively and 1, 3, and 6 months postoperatively. Subbasal nerve images were analyzed to assess nerve regeneration.
  
  
  RESULTS
  Postoperatively, tear breakup time decreased significantly and had not returned to the preoperative level by 6 months after surgery. There were no significant differences in the phenol red thread test results before and after LASEK. Central corneal sensation decreased significantly 1 month after LASEK and returned to normal levels 3 months after surgery. Nerve fiber density, nerve branch density, and nerve fiber length and width decreased significantly after LASEK and had not returned to preoperative levels 6 months after surgery. Subbasal nerve fibers retained their vertical orientation after LASEK. There were no significant correlations between the length and density of subbasal nerve fibers and central corneal sensitivity, tear volume, or breakup time after surgery.
  
  
  CONCLUSIONS
  Subbasal nerves were injured by LASEK and had not returned to preoperative levels 6 months after surgery. Corneal sensitivity was reduced after LASEK and returned to normal levels 3 months after surgery.
authors.affiliation: Royal Eye Hospital, Manchester, United Kingdom. taym@scs-net.org
authors.forename: Taym
authors.initials: T
authors.lastname: Darwish
authors.forename: Arun
authors.initials: A
authors.lastname: Brahma
authors.forename: Nathan
authors.initials: N
authors.lastname: Efron
authors.forename: Clare
authors.initials: C
authors.lastname: O'Donnell
mesh_terms: D000328:Adult; D004396:Coloring Agents; D003315:Cornea / Q000294:innervation* / Q000502:physiology; D005260:Female; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D009412:Nerve Fibers / Q000502:physiology; D009416:Nerve Regeneration / Q000502:physiology*; D009882:Ophthalmic Nerve / Q000502:physiology*; D010637:Phenolsulfonphthalein; D011446:Prospective Studies; D012677:Sensation / Q000502:physiology; D013666:Tears / Q000502:physiology
chemical_list: D004396:Coloring Agents; D010637:Phenolsulfonphthalein