title: Intrastromal ring segment insertion using a femtosecond laser to correct pellucid marginal corneal degeneration.
abstract: OBJECTIVE
  To assess the outcomes of intrastromal ring segment (Intacs, Addition Technology) implantation using a femtosecond laser in patients with pellucid marginal corneal degeneration.
  
  
  METHODS
  Kudret Eye Hospital, Ankara, Turkey.
  
  
  METHODS
  In this retrospective noncomparative case series, 9 eyes of 6 patients with pellucid marginal corneal degeneration had implantation of Intacs segments by a femtosecond laser technique. Preoperative and postoperative evaluations included slitlamp examination, uncorrected (UCVA) and best corrected (BCVA) visual acuities, and keratometry by a Pentacam Scheimpflug camera (Oculus Opticgerate GmbH). All parameters were reviewed within 6 months.
  
  
  RESULTS
  Intacs were successfully implanted in all eyes. The UCVA significantly improved from preoperatively to 6 months after Intacs implantation (mean 0.18 +/- 0.24 [SD] and 0.53 +/- 0.23, respectively). The mean difference between the preoperative and postoperative UCVA was 3.5 +/- 1.6 lines (P = .008). The BCVA also significantly improved from preoperatively to 6 months after implantation (mean 0.63 +/- 0.26 and 0.85 +/- 0.18 at 6 months, respectively). The Snellen BCVA was 1.0 in 5 eyes postoperatively. The mean difference between preoperative and postoperative BCVA was 2.3 +/- 51 lines (P = .011). The mean preoperative spherical refraction decreased from -3.86 +/- 2.91 diopters (D) to -2.77 +/- 1.43D (P = .091) and the mean cylindrical refraction, from -2.41 +/- 2.27 D to -0.94 +/- 1.07 D (P = .046). The mean central corneal curvature decreased from 48.20 +/- 4.19 D preoperatively to 46.90 +/- 5.00 D (P = .008) at 6 months and the mean posterior elevation, from 53.88 +/- 21.72 microm to 32.55 +/- 11.23 microm (P = .008).
  
  
  CONCLUSIONS
  Intacs insertion using a femtosecond laser was safe and efficient in the correction of pellucid marginal corneal degeneration.
authors.affiliation: Kudret Eye Hospital, Ankara, Turkey. ertanaylin@hotmail.com
authors.forename: Aylin
authors.initials: A
authors.lastname: Ertan
authors.forename: Mehmet
authors.initials: M
authors.lastname: Bahadir
mesh_terms: D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery; D003317:Corneal Dystrophies, Hereditary / Q000503:physiopathology / Q000601:surgery*; D003319:Corneal Stroma / Q000503:physiopathology / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D053685:Laser Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D019919:Prosthesis Implantation / Q000379:methods*; D012189:Retrospective Studies; D014792:Visual Acuity