title: Evaluation of the outcomes of corneal collagen cross-linking in progressive keratoconic eyes.
abstract: BACKGROUND
  Corneal collagen cross-linking (CXL) is gaining popularity as a treatment in arresting the progression of keratoconus. It is a relatively new therapy using ultraviolet-A (UVA) with a photosensitizer to increase corneal stiffness. The purpose of this study was to evaluate visual, keratometric and topographic outcomes after corneal CXL in progressive keratoconic eyes.
  
  
  METHODS
  In this prospective nonrandomized clinical study, 140 eyes of 110 patients with progressive keratoconus were treated by combined riboflavin/UVA CXL. Mean sphere, mean cylinder uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refractive spherical equivalent, corneal topography, pachymetry, and endothelial cell morphology were examined preoperatively and 12-24 months postoperatively.
  
  
  RESULTS
  The preoperative mean sphere was -3.33 ± 3.13 diopter (D) and decreased to -3.09 ± 3.09 D (P = 0.007). The preoperative mean cylinder was -4.05 ± 2.29 D and changed to -3.79 ± 2.23 D (P = 0.011). UDVA changed from 0.95 ± 0.64 logarithm of the minimum angle of resolution (logMAR) to 0.85 ± 0.59 logMAR (P = 0.003). Thirty-five eyes (25%) gained one or more lines of preoperative UDVA, 87 eyes (62.1%) did not change and 18 eyes (12.8%) lost one or more lines of the preoperative UDVA. CDVA in 80% of the patients remained stable (no lines lost). Statistical analysis of keratometry, pachymetry, and endothelial cell count did not show the significant difference after surgery.
  
  
  CONCLUSIONS
  Our study showed improvement in visual and refractive results of the corneal CXL and confirmed that CXL is the safe and effective procedure.
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Kobra
authors.initials: K
authors.lastname: Nasrollahi
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran ; Department Research and Development, Parsian Clinic of Ophthalmology, Isfahan, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ghoreishi
authors.affiliation: Department Research and Development, Parsian Clinic of Ophthalmology, Isfahan, Iran.
authors.forename: Shahriar
authors.initials: S
authors.lastname: Hanjani
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Ziaie
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran ; Department Research and Development, Parsian Clinic of Ophthalmology, Isfahan, Iran.
authors.forename: Mohadeseh
authors.initials: M
authors.lastname: Mohammadinia
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Kabiri
authors.affiliation: Department Research and Development, Parsian Clinic of Ophthalmology, Isfahan, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Bahadoran
keywords: Collagen cross-linking; progressive keratoconus; ultraviolet irradiation