title: Laser in situ keratomileusis with the Nidek EC-5000 excimer laser for astigmatism greater than 4.00 D.
abstract: OBJECTIVE
  To evaluate laser in situ keratomileusis (LASIK) performed with the Nidek EC-5000 excimer laser in 66 astigmatic eyes with cylinder from 4.00 to 8.00 D.
  
  
  METHODS
  LASIK was performed with the Nidek EC-5000 excimer laser in 66 astigmatic eyes with cylinder from 4.00 to 8.00 D. Based on Chayet's nomogram, ablation zone diameters were 5.5 mm (steep meridian ablation) to 7.5 mm (flat meridian ablation). In eyes with simple myopic astigmatism, mixed astigmatism, and compound myopic astigmatism (low sphere), ablation was performed in both meridians. In eyes with simple hyperopic astigmatism, ablation was performed in the flat meridian alone. In eyes with compound hyperopic astigmatism, ablation zone diameter was 5.5 mm and the transition zone was 7.5 mm.
  
  
  RESULTS
  Uncorrected visual acuity was 20/40 or better in 89% of eyes and was equal to preoperative best spectacle-corrected visual acuity in 62% of eyes. No eyes lost lines of best spectacle-corrected visual acuity.
  
  
  CONCLUSIONS
  Using the Nidek EC-5000 excimer laser, we had satisfactory results in the treatment of astigmatic eyes with cylinder from 4.00 to 8.00 D, based on Chayet's nomogram.
authors.affiliation: Laser Vision, Guarulhos, São Paulo, Brazil. marcelolui@cmcsidimagem.com.br
authors.forename: Marcelo Mastromonico
authors.initials: MM
authors.lastname: Lui
authors.forename: Marcia Ap Grandini
authors.initials: MA
authors.lastname: Silas
authors.forename: Benny
authors.initials: B
authors.lastname: Apelbaum
authors.forename: Akioshi
authors.initials: A
authors.lastname: Oshima
mesh_terms: D001251:Astigmatism / Q000601:surgery*; D003315:Cornea / Q000601:surgery*; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation / Q000379:methods*; D012029:Refraction, Ocular; D012449:Safety; D016896:Treatment Outcome; D014792:Visual Acuity