title: Comparative results between standard and bitoric nomograms for astigmatism correction.
abstract: OBJECTIVE
  To investigate results of excimer laser correction for mixed astigmatism, using two kinds of corneal photoablation; bitoric nomograms for cylinder and standard monotoric procedures.
  
  
  METHODS
  Intrastromal photoablation was performed with the Nidek EC-5000 excimer laser and a lamellar keratotomy was created with the Hansatome microkeratome. We selected 46 cases with mixed astigmatism. The first group included 28 eyes (average cylinder 4.15 +/- 0.86 D, sphere 1.37 +/- 0.18 D). In this group, procedures were performed using bitoric nomograms. The second group included 18 eyes (average cylinder 4.05 +/- 0.64 D, sphere 1.67 +/- 0.23 D). In this group ablation was performed with monotoric nomograms.
  
  
  RESULTS
  After 6 months in the bitoric group, average residual cylinder was 1.49 +/- 0.24 D, and sphere was -0.57 +/- 0.31 D. In seven cases (25%), re-ablations for astigmatism correction were needed. In the monotoric group, average postoperative cylinder was 1.89 +/- 0,39 D, and sphere was 0.77 +/- 0.28 D. In eight cases (44%), retreatments were planned.
  
  
  CONCLUSIONS
  Bitoric ablations for astigmatic corrections resulted in a decreased frequency of reablation as compared to standard monotoric procedures.
authors.affiliation: New Line Vision Ophthalmology Research Centre, Moscow, Russia. nlvision@online.ru
authors.forename: V M
authors.initials: VM
authors.lastname: Sheludchenko
authors.forename: T
authors.initials: T
authors.lastname: Fadeykina
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D003319:Corneal Stroma / Q000503:physiopathology / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D012029:Refraction, Ocular / Q000502:physiology; D012086:Reoperation; D013524:Surgical Flaps; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology