title: Subbasal nerve fiber regeneration after LASIK and LASEK assessed by noncontact esthesiometry and in vivo confocal microscopy: prospective study.
abstract: OBJECTIVE
  To evaluate recovery of the corneal subbasal nerve plexus and corneal sensitivity after myopic laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratectomy (LASEK).
  
  
  METHODS
  Manchester Centre for Vision, Royal Eye Hospital, Manchester, United Kingdom.
  
  
  METHODS
  Thirty LASEK patients and 20 LASIK patients had slit-scanning confocal microscopy and noncontact corneal esthesiometry preoperatively and 1, 3, and 6 months after surgery. Images of the subbasal nerve plexus were analyzed using customized software to evaluate nerve regeneration.
  
  
  RESULTS
  Central corneal sensitivity decreased significantly 1 month after LASEK and LASIK and returned to normal levels after 3 months. Corneal subbasal nerve fiber density, nerve branch density, nerve fiber length, and nerve fiber width decreased significantly 1 month after LASIK and had not returned to the preoperative levels by 6 months. Nerve fiber tortuosity decreased significantly 1 month after LASEK and returned to the preoperative levels 3 months after surgery. There were no significant differences in nerve fiber tortuosity before and after LASIK. Neither corneal sensitivity nor nerve fiber morphology was different between the 2 groups at any postoperative visit.
  
  
  CONCLUSIONS
  Corneal sensitivity and subbasal nerve morphology were adversely affected by LASEK and LASIK. Corneal sensitivity recovered 3 months after the procedure, but subbasal nerves were still abnormal after 6 months. Despite the different forms of surgical trauma to corneal nerves with LASIK and LASEK, there was no apparent difference in the time course of recovery of corneal structure and function.
authors.affiliation: Royal Eye Hospital, Manchester, University of Manchester, 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: Clare
authors.initials: C
authors.lastname: O'Donnell
authors.forename: Nathan
authors.initials: N
authors.lastname: Efron
mesh_terms: D000328:Adult; D003315:Cornea / Q000294:innervation*; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D006987:Hypesthesia / Q000503:physiopathology; D049008:Keratectomy, Subepithelial, Laser-Assisted; D020731:Keratomileusis, Laser In Situ; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D009412:Nerve Fibers / Q000502:physiology*; D009416:Nerve Regeneration / Q000502:physiology*; D009882:Ophthalmic Nerve / Q000502:physiology*; D011446:Prospective Studies; D020127:Recovery of Function; D013997:Time Factors