title: Intacs implantation using a femtosecond laser for management of keratoconus: Comparison of 306 cases in different stages.
abstract: OBJECTIVE
  To evaluate the efficacy of intrastromal ring segment (Intacs, Addition Technology, Inc.) implantation and analyze outcomes according to different keratoconus stages.
  
  
  METHODS
  Kudret Eye Hospital, Ankara, Turkey.
  
  
  METHODS
  In this retrospective noncomparative case series, 306 keratoconic eyes of 255 patients who had Intacs segment implantation were reviewed. Patients were grouped according to the Amsler-Krumeich keratoconus classification (stage II, 155 eyes; stage III, 83 eyes; stage IV, 68 eyes). The uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), central corneal curvature, spherical and cylindrical manifest refractions, and central corneal thickness were analyzed and compared according to keratoconus stage.
  
  
  RESULTS
  At a mean follow-up of 10.39 months +/- 5.04 (SD), the BCVA improved in 71.6% of eyes and the UCVA improved in 75.7% of eyes. The mean keratometry (K) decreased from 50.7 diopters (D) to 47.9 D (P<.05); the mean manifest spherical refraction, from -6.04 D to -3.09 D (P<.05); and the mean manifest cylindrical refraction, from -4.11 D to -3.82 D (P>.05). The changes in BCVA and manifest spherical and cylindrical refractions were not statistically different between the different keratoconus stages (P >.05). There was less change in UCVA and more improvement in the mean K value after Intacs treatment in stage IV than in the other stages (P<.05, analysis of variance).
  
  
  CONCLUSIONS
  Intacs treatment with a femtosecond laser was effective for management of keratoconus of all stages. Improvement in UCVA may be less in severe keratoconus than in moderate keratoconus.
authors: Kudret Eye Hospital, Kennedy Caddesi No. 71, Kavaklidere, Ankara, Turkey. ertanaylin@hotmail.com
authors: Aylin
authors: A
authors: Ertan
authors: Günhal
authors: G
authors: Kamburoğlu
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003319:Corneal Stroma / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000145:classification / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019904:Polymethyl Methacrylate; D019736:Prostheses and Implants; D019919:Prosthesis Implantation / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology
chemical_list: D019904:Polymethyl Methacrylate