title: Clinical outcomes after intrastromal corneal ring segments reoperation in keratoconus patients.
abstract: OBJECTIVE
  To evaluate the clinical outcomes after Ferrara intrastromal corneal ring segments (ICRS) reoperation in patients with keratoconus.
  
  
  METHODS
  A total of 37 keratoconus eyes implanted with intrastromal corneal ring segments, which had an ICRS exchange, addition, reposition or removal were evaluated. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), keratometry (K), asphericity (Q) and pachymetry at the thinnest point (PTP) of the cornea were evaluated using a corneal tomography (Oculus Pentacam, USA).
  
  
  RESULTS
  The mean follow-up time after the reoperation was 30.5±9.7 months. The mean UCVA improved from 20/300 to 20/80 (P=0.005); the mean BCVA improved from 20/160 to 20/50 (P=0.0002), the mean keratometry reduced from 49.33±4.19D to 46.16±3.90D (P=0.0001), the mean pachymetry at the thinnest point increased from 450±42.9μm to 469±40.8μm (P=0.0001). The asphericity increased from -0.84±0.74 to -0.35±0.81 (P=0.15) and the spherical equivalent reduced from -4.64±4.87D to -3.04±3.45D (P=0.137). The changes in the asphericity and spherical equivalent were not statistically significant.
  
  
  CONCLUSIONS
  Ferrara ICRS implantation showed to be a reversible and readjustable surgical procedure for keratoconus treatment. Good outcomes can be obtained even after removal, addition, reposition or exchange of ICRS.
authors.affiliation: Paulo Ferrara Eye Clinic, Belo Horizonte 30110-031, Brazil.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Torquetti
authors.affiliation: Paulo Ferrara Eye Clinic, Belo Horizonte 30110-031, Brazil ; Fernandez-Vega Eye Institute, Oviedo 33012, Spain.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Ferrara
authors.affiliation: Hilton Rocha Foundation, Belo Horizonte 30210-090, Brazil.
authors.forename: Franklin
authors.initials: F
authors.lastname: Almeida
authors.affiliation: Hilton Rocha Foundation, Belo Horizonte 30210-090, Brazil.
authors.forename: Leandro
authors.initials: L
authors.lastname: Cunha
authors.affiliation: Paulo Ferrara Eye Clinic, Belo Horizonte 30110-031, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Ferrara
authors.affiliation: Fernandez-Vega Eye Institute, Oviedo 33012, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Merayo-Lloves
keywords: intrastromal corneal ring segments; keratoconus; reoperation