title: Ferrara intrastromal corneal rings for the correction of keratoconus.
abstract: OBJECTIVE
  To evaluate the safety and efficacy of Ferrara intrastromal corneal rings in the treatment of eyes with keratoconus without central corneal scarring.
  
  
  METHODS
  Vlemma Eye Institute, Athens, Greece.
  
  
  METHODS
  Twenty-six patients with bilateral keratoconus, clear central corneas, and contact lens intolerance participated in the study. Videokeratographic corneal topography and ultrasonic pachymetry were performed in all eyes to identify the cone area and to select the thickness of the segments to be implanted, respectively. Ferrara intrastromal corneal rings were implanted around the center of the cone in 1 eye of each patient.
  
  
  RESULTS
  The minimum follow-up after ring implantation was 6 months. In 2 cases, the rings had to be removed early in the postoperative period because of superficial implantation in 1 patient and asymmetrical placement in the other. The rest of the operated eyes demonstrated a reduction in astigmatism and spherical correction and improved uncorrected visual acuity. No eye lost best corrected visual acuity.
  
  
  CONCLUSIONS
  Ferrara intrastromal corneal rings reduced corneal steepening and normalized the central cornea in eyes with keratoconus. Ferrara ring implantation was a safe procedure that may be considered in patients who are unable to have other surgical techniques, particularly contact-lens-intolerant keratoconus patients whose only option is corneal transplantation.
authors.affiliation: Vlemma Eye Institute, Athens, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Siganos
authors.forename: Paulo
authors.initials: P
authors.lastname: Ferrara
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Chatzinikolas
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Bessis
authors.forename: Georgios
authors.initials: G
authors.lastname: Papastergiou
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000209:etiology / Q000503:physiopathology; D019781:Corneal Topography; D020878:Device Removal; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D008297:Male; D019736:Prostheses and Implants / Q000009:adverse effects; D012449:Safety; D014463:Ultrasonography; D014792:Visual Acuity