title: Clinical analysis of central islands after laser in situ keratomileusis.
abstract: OBJECTIVE
  To analyze the incidence and clinical characteristics of central islands after laser in situ keratomileusis (LASIK) and to elucidate factors associated with their formation.
  
  
  METHODS
  Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
  
  
  METHODS
  Laser in situ keratomileusis was performed in 103 eyes of 61 patients with myopia ranging from -4.0 to -13.5 diopters (D) using the Hansatome (Chiron) and SVS Apex Plus (version 3.2.1) excimer laser (Summit Technology) in which the anti-central-island program was implemented. After 1 week, corneal topography (Orbscan, Orbtek) was done and manifest refraction and visual acuity were measured.
  
  
  RESULTS
  Postoperatively, the mean uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were 0.12 and 0.06 (logMAR scale), respectively, and the mean refractive error (spherical equivalent) was 0.07 D +/- 0.76 (SD). On topographic examination, a central island was defined as an area of higher refractive power of more than 1.5 D and 2.5 mm or more in diameter. Budding or isolated central islands were observed in 12 eyes of 12 patients (11.7%). The peak, height, and area of the islands were 41.5 +/- 3.1 D, 5.6 +/- 1. 9 D, and 3.5 +/- 1.1 mm(2), respectively. In the eyes with central islands, there were statistically significant differences in the postoperative change in UCVA and BCVA (P <.05). There was no significant correlation between the occurrence of a central island and preoperative refractive error, corneal thickness, age, or in sex and correction of astigmatism (P >.05).
  
  
  CONCLUSIONS
  Despite use of the anti-central-island pretreatment program, the occurrence of central islands after LASIK was significant, as in photorefractive keratectomy. Further studies of the effect of central islands on surgical results and clinical progress and measures to prevent the occurrence are needed.
authors.affiliation: Department of Ophthalmology, Samsung Medical Center School of Medicine, Sungkyunkwan University, Seoul, South Korea.
authors.forename: S W
authors.initials: SW
authors.lastname: Kang
authors.forename: E S
authors.initials: ES
authors.lastname: Chung
authors.forename: W J
authors.initials: WJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000209:etiology* / Q000473:pathology; D003315:Cornea / Q000473:pathology / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D011379:Prognosis; D012029:Refraction, Ocular; D012189:Retrospective Studies; D014792:Visual Acuity