title: Accuracy and predictability of the compensatory function of Orbscan II in intraocular pressure measurements after laser in situ keratomileusis.
abstract: OBJECTIVE
  To evaluate the usefulness of the compensatory function of Orbscan II (Orbtek, Bausch & Lomb) for measuring postoperative intraoperative pressure (IOP) in laser in situ keratomileusis (LASIK) patients.
  
  
  METHODS
  Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Ilsan, Korea.
  
  
  METHODS
  Two hundred ten patients had LASIK using the Hansatome microkeratome (Bausch & Lomb) and the MEL 70 G-scan laser (Aesclepion-Meditec) and were examined retrospectively. The patients included in the study were divided into 2 groups: Group 1, 123 eyes with less than -6.0 diopters (D) of myopia; Group 2, 60 eyes with more than -6.0 D of myopia. The IOP was measured preoperatively and 2 and 4 weeks after LASIK using a noncontact tonometer (NCT CT-60, Topcon). The results were corrected with the Orbscan II program.
  
  
  RESULTS
  The mean IOPs in Group 1 were 16.35 mm Hg +/- 2.90 (SD) preoperatively, 10.80 +/- 2.21 mm Hg at 2 weeks, and 10.63 +/- 2.28 mm Hg at 4 weeks. After compensation with Orbscan II, the 2-week and 4-week values were 16.81 +/- 3.14 mm Hg and 16.68 +/- 3.22 mm Hg, respectively. The mean IOPs in Group 2 were 17.63 +/- 2.93 mm Hg, 10.07 +/-1.55 mm Hg, and 10.43 +/- 1.84 mm Hg, respectively; after compensation, they were 18.40 +/- 4.09 mm Hg and 18.05 +/- 4.09 mm Hg, respectively. After compensation with Orbscan II, there were no statistically significant differences between the preoperative and postoperative IOPs.
  
  
  CONCLUSIONS
  Orbscan II may help predict actual IOP values after LASIK and avoid the misinterpretation of high IOPs as normal IOPs.
authors.affiliation: Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Ilsan, Korea. dhlee@ilsanpaik.ac.kr
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Lee
authors.forename: Sejung
authors.initials: S
authors.lastname: Seo
authors.forename: Soo-Cheol
authors.initials: SC
authors.lastname: Shin
authors.forename: Eui-Hong
authors.initials: EH
authors.lastname: Chung
authors.forename: Tim T
authors.initials: TT
authors.lastname: Turner
mesh_terms: D000328:Adult; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D019781:Corneal Topography / Q000379:methods*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011182:Postoperative Care; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014065:Tonometry, Ocular / Q000379:methods*