title: Accelerated versus conventional corneal collagen cross-linking in patients with keratoconus: an intrapatient comparative study.
abstract: OBJECTIVE
  To compare the outcomes of the conventional and accelerated corneal collagen cross-linking (CXL) in patients with bilateral progressive keratoconus (KC).
  
  
  METHODS
  Fifteen consecutive patients with bilateral progressive KC were enrolled. In each patient, the fellow eyes were randomly assigned to the conventional CXL (3 mW/cm2for 30 min) or accelerated CXL (ACXL) (9 mW/cm2for 10 min) groups. Manifest refraction; uncorrected and corrected distant visual acuity; maximum and mean keratometry; corneal hysteresis and corneal resistance factor; endothelial cell density and morphology; central corneal thickness; and wavefront aberrations were measured before and 12 months after the CXL.
  
  
  RESULTS
  Manifest refraction spherical equivalent and refractive cylinder improved significantly only in conventional group. Uncorrected and corrected distant visual acuity did not change significantly in either group. Also there was no significant change in the maximum and mean keratometry after 12 months. There was significant decrease in central corneal thickness in both groups which was more prominent in conventional group. Endothelial cell density reduced only in the conventional group which was not statistically significant (P = 0.147). CH, CRF, and wavefront aberrations did not change significantly in either group. We did not observe any significant difference in the changes of the variables between the two groups.
  
  
  CONCLUSIONS
  Accelerated CXL with 9 mW/cm2irradiation for 10 min had similar refractive, visual, keratometric, and aberrometric results and less adverse effects on the corneal thickness and endothelial cells as compared with the conventional method after 12 months follow-up. However, randomized clinical trials with longer follow-ups and larger sample sizes are needed.
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. sadoughi_mm@yahoo.com.|Department of Ophthalmology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. sadoughi_mm@yahoo.com.
authors.forename: Mohammad Mehdi
authors.initials: MM
authors.lastname: Sadoughi
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Bahram
authors.initials: B
authors.lastname: Einollahi
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Baradaran-Rafii
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Danial
authors.initials: D
authors.lastname: Roshandel
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Hasani
authors.affiliation: Scientific Educational Ophthalmology Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Nazeri
mesh_terms: D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000378:metabolism*; D003315:Cornea / Q000503:physiopathology; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012256:Riboflavin / Q000627:therapeutic use*; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin
keywords: Accelerated; Corneal collagen cross-linking; Keratoconus; Keratometry