title: Corneal endothelial cell density after femtosecond thin-flap LASIK and PRK for myopia: a contralateral eye study.
abstract: OBJECTIVE
  To compare the effect of femtosecond thinflap LASIK and photorefractive keratectomy (PRK) on postoperative endothelial cell density.
  
  
  METHODS
  In a prospective, randomized, contralateral, single-center clinical trial, 25 patients (mean age: 30+/-5 years [range: 21 to 38 years]) underwent PRK in one eye and thin-flap LASIK in the fellow eye for the correction of myopia using a wavefront-guided platform. The central corneal endothelial cell density was measured using the NIDEK Confoscan 4 preoperatively, and at 1 and 3 months postoperatively. Changes in endothelial cell density were analyzed over time between the two refractive techniques.
  
  
  RESULTS
  In PRK, the average preoperative endothelial cell density was 3011+/-329 cells/mm(2), which decreased to 2951+/-327 cells/mm(2) at 1 month (P=.5736) and 2982+/-365 cells/mm(2) at 3 months (P=.6513). In thinflap LASIK, the average preoperative endothelial cell density was 2995+/-325 cells/mm(2), which decreased to 2977+/-358 cells/mm(2) at 1 month (P=.5756) and 2931+/-369 cells/mm(2) at 3 months (P=.4106). No statistically significant difference was found between the two groups at 1 (P=.7404) or 3 (P=.3208) months postoperatively.
  
  
  CONCLUSIONS
  No statistically significant change was noted in endothelial cell density following either PRK or thin-flap LASIK for the treatment of myopia. Furthermore, no statistically significant difference was found between the two groups out to 3 months postoperatively, indicating that thin-flap LASIK is as safe as PRK with regards to endothelial health.
authors.affiliation: Durrie Vision, Overland Park, KS, USA.
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Smith
authors.forename: George O
authors.initials: GO
authors.lastname: Waring
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Durrie
authors.forename: Jason E
authors.initials: JE
authors.lastname: Stahl
authors.forename: Priscilla
authors.initials: P
authors.lastname: Thomas
mesh_terms: D000328:Adult; D002452:Cell Count; D003319:Corneal Stroma / Q000601:surgery; D019781:Corneal Topography; D004728:Endothelium, Corneal / Q000473:pathology*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D013524:Surgical Flaps; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult