title: [Management and retreatment of laser in situ keratomileusis flap buttonhole].
abstract: OBJECTIVE
  To examine the etiology and management of buttonholes created during laser in situ keratomileusis (LASIK).
  
  
  METHODS
  Retrospective review of case records of 1010 eyes of 514 patients who underwent LASIK. Four eyes of 4 patients developed a flap buttonhole, and subsequent laser ablation was not performed. Retreatment was done after a mean interval of 6 months.
  
  
  RESULTS
  The etiology of a buttonhole was considered to be misuse of microkeratome in 1 patient and desiccation of the cornea in 2 patients, and could not be determined in 1 patient. Uncorrected visual acuity in those 4 patients was 1.2, 1.2, 0.9, and 1.5 respectively, after retreatment. The mean preoperative spherical equivalent was -5.47 diopters(D), and the mean spherical equivalent before retreatment was -5.19 D. The mean preoperative corneal refractive power of 43.53 D flattened to 42.88 D before retreatment. The mean preoperative corneal astigmatism of 1.63 D increased to 2.06 D before retreatment.
  
  
  CONCLUSIONS
  Misuse of microkeratome and desiccation of the cornea may cause a buttonhole. If a buttonhole is created, retreatment by LASIK scheduled several months later may achieve good uncorrected visual acuity.
authors.affiliation: Department of Ophthalmology, Yatsuo General Hospital, Toyama, Japan.
authors.forename: Kosaku
authors.initials: K
authors.lastname: Tagawa
authors.forename: Tomomi
authors.initials: T
authors.lastname: Higashide
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Sugiyama
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kawasaki
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects*; D008297:Male; D011183:Postoperative Complications; D012086:Reoperation