title: Intrastromal corneal ring segment implantation to correct astigmatism after penetrating keratoplasty.
abstract: OBJECTIVE
  To evaluate the clinical outcomes of implantation of Ferrara intrastromal corneal ring segments (ICRS) in patients with astigmatism after penetrating keratoplasty (PKP).
  
  
  METHODS
  Private clinic, Belo Horizonte, Brazil.
  
  
  METHODS
  Retrospective consecutive case series.
  
  
  METHODS
  Chart records of post-PKP patients who had ICRS implantation from May 2005 to September 2009 were retrospectively reviewed. The following parameters were studied: corrected distance visual acuity (CDVA), keratometry (K) values, spherical equivalent (SE), spherical refractive error, corneal topographic astigmatism, minimum K, and maximum K.
  
  
  RESULTS
  The study evaluated 59 eyes (54 patients). The mean CDVA (logMAR) improved from 0.45 ± 0.17 (SD) (range 0.18 to 1.00) to 0.30 ± 0.17 (range 0.00 to 1.00). The mean SE was -6.34 ± 3.40 diopters (D) (range 0.37 to -16.50 D) preoperatively and -2.66 ± 2.52 D (range 0.87 to -10.50 D) postoperatively. The mean spherical refractive error decreased from -7.10 ± 3.07 D (range 2.15 to 16.68 D) preoperatively to -3.46 ± 2.05 D (range 0.88 to 10.79 D) postoperatively. No patient lost visual acuity. The mean corneal topographic astigmatism decreased from 3.37 ± 1.51 D preoperatively to 1.69 ± 1.04 D postoperatively. The mean maximum K value decreased from 48.09 ± 2.56 D to 44.17 ± 2.67 D and the mean minimum K value, from 44.90 ± 2.54 D to 42.46 ± 2.63 D. All changes were statistically significant (P<.0001).
  
  
  CONCLUSIONS
  Intrastromal corneal ring segments effectively reduced corneal cylinder in patients with astigmatism after PKP.
authors.affiliation: Ennio Coscarelli Eye Clinic, Belo Horizonte, Brazil.
authors.forename: Sandro
authors.initials: S
authors.lastname: Coscarelli
authors.forename: Guilherme
authors.initials: G
authors.lastname: Ferrara
authors.forename: Jose F
authors.initials: JF
authors.lastname: Alfonso
authors.forename: Paulo
authors.initials: P
authors.lastname: Ferrara
authors.forename: Jesús
authors.initials: J
authors.lastname: Merayo-Lloves
authors.forename: Luana P N
authors.initials: LP
authors.lastname: Araújo
authors.forename: Aydano P
authors.initials: AP
authors.lastname: Machado
authors.forename: João Marcelo
authors.initials: JM
authors.lastname: Lyra
authors.forename: Leonardo
authors.initials: L
authors.lastname: Torquetti
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D001672:Biocompatible Materials; D003319:Corneal Stroma / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015948:Keratoplasty, Penetrating; D008297:Male; D019904:Polymethyl Methacrylate; D011183:Postoperative Complications; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology
chemical_list: D001672:Biocompatible Materials; D019904:Polymethyl Methacrylate