title: Intrastromal corneal ring segment implantation for ectasia after refractive surgery.
abstract: OBJECTIVE
  To evaluate the clinical outcomes of implantation of Ferrara intrastromal corneal ring segments (ICRS) in patients with corneal ectasia after refractive surgery.
  
  
  METHODS
  Private clinic, Belo Horizonte, Brazil.
  
  
  METHODS
  Charts of patients with corneal ectasia after refractive surgery were retrospectively reviewed. The following parameters were studied: uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometry, corneal asphericity, and pachymetry. All patients were evaluated by Scheimpflug scanning-slit tomography (Pentacam).
  
  
  RESULTS
  Twenty-five eyes (20 patients) with corneal ectasia (20 after laser in situ keratomileusis, 4 after radial keratotomy, 1 after photorefractive keratectomy) were evaluated. Postoperatively, the mean UDVA increased from 20/185 to 20/66 (P = .005) and the mean CDVA, from 20/125 to 20/40 (P = .008). The mean asphericity decreased from -0.95 preoperatively to -0.23 postoperatively (P = .006). The mean pachymetry at the apex of the cornea increased from 457.7 microm +/- 48.7 (SD) preoperatively to 466.2 +/- 49.8 mum postoperatively (P = .025) and the mean pachymetry at the thinnest point, from 436.3 +/- 46.2 microm to 453.9 +/- 49.3 microm (P = .000). The mean keratometry decreased from 45.41 +/- 5.63 diopters (D) to 42.88 +/- 4.44 D, respectively; the decrease was statistically significant (P = .000).
  
  
  CONCLUSIONS
  Intrastromal corneal ring segment implantation significantly improved UDVA and CDVA in patients with corneal ectasia.
authors.affiliation: Private clinic, Belo Horizonte, Brazil.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Torquetti
authors.forename: Paulo
authors.initials: P
authors.lastname: Ferrara
mesh_terms: D000328:Adult; D001672:Biocompatible Materials; D003316:Corneal Diseases / Q000209:etiology / Q000601:surgery*; D003319:Corneal Stroma / Q000601:surgery*; D004108:Dilatation, Pathologic / Q000209:etiology / Q000601:surgery; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects; D007646:Keratotomy, Radial / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D018903:Photorefractive Keratectomy / Q000009:adverse effects; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D054140:Refractive Surgical Procedures / Q000009:adverse effects*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology
chemical_list: D001672:Biocompatible Materials