title: Laser in situ keratomileusus for mixed and simple myopic astigmatism with the Nidek EC-5000 Laser.
abstract: OBJECTIVE
  To evaluate the visual and refractive results of laser in situ keratomileusis (LASIK) for mixed and simple myopic astigmatism using bitoric ablation.
  
  
  METHODS
  A retrospective study was performed in 65 eyes of 38 consecutive patients to evaluate uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA) and cyclopegic and manifest refraction, before and 3 and 6 months after LASIK (Moria LSK-ONE microkeratome, Nidek EC-5000 excimer laser).
  
  
  RESULTS
  At 3 and 6 months after LASIK, 40 eyes of 24 patients (64.5%) were available for follow-up examination. Mean age was 25.9 +/- 6.6 years (range 18 to 43 yr). Mean preoperative manifest spherical equivalent refraction was -1.40 +/- 0.80 D (range -3.80 to +0.50 D) mean preoperative cylinder was -3.30 +/- 1.30 D (range -1.00 to -6.00 D). At 6 months follow-up, mean manifest spherical equivalent refraction was +0.30 +/- 0.46 D (range -0.38 to +1.88 D), mean cylinder was -0.73 +/- 0.61 D (range -2.25 to 0 D). There was a 77.8% decrease in astigmatism magnitude. According to vector analysis, mean achieved vector magnitude was 80% of intended. Fifty percent (20 eyes) had a cylinder within +/- 0.50 D of emmetropia. Twenty-three eyes (57.5%) had a spherical component within +/- 0.50 D. Eighty-five percent (34 eyes) had postoperative UCVA of 20/40 or better. Ten percent (four eyes) lost two lines of Snellen BSCVA, whereas 35% (14 eyes) gained one or more lines.
  
  
  CONCLUSIONS
  Bitoric LASIK with the Moria LSK-ONE microkeratome and Nidek EC-5000 excimer laser was effective and safe for the reduction of cylinder in mixed and simple myopic astigmatism. Moderate undercorrection of the cylinder was evident.
authors.affiliation: Centro Oftalmológico de Valencia-CEOVAL, Venezuela.
authors.forename: Lizbeth
authors.initials: L
authors.lastname: Rueda
authors.forename: Angel
authors.initials: A
authors.lastname: Pineda-Fernández
authors.forename: David
authors.initials: D
authors.lastname: Huang
authors.forename: Jorge
authors.initials: J
authors.lastname: Nur
mesh_terms: D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000601:surgery*; D003315:Cornea / Q000601:surgery*; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation / Q000379:methods*; D053685:Laser Therapy; D009216:Myopia / Q000601:surgery*; D011183:Postoperative Complications; D012029:Refraction, Ocular; D012189:Retrospective Studies; D012449:Safety; D016896:Treatment Outcome; D014792:Visual Acuity