A randomized controlled trial of corneal collagen cross-linking in progressive keratoconus: preliminary results

J Refract Surg. 2008 Sep;24(7):S720-5. doi: 10.3928/1081597X-20080901-15.

Abstract

Purpose: This prospective, randomized, controlled trial aims to provide evidence in relation to the efficacy and safety of corneal collagen cross-linking (CXL) in the management of progressive keratoconus.

Methods: Eligible eyes were separately randomized into either treatment or control groups. Collagen crosslinking was performed using 0.1% riboflavin (in 20% dextran T500) and ultraviolet A (UVA) irradiation (370 nm, 3 mW/cm2, 30 min) in accordance with a previously published protocol. At each review, a full clinical ophthalmic examination was performed including endothelial cell count and confocal microscopy.

Results: To date, 66 eyes of 49 patients with documented progression of keratoconus have been enrolled and randomized. Interim analysis of treated eyes showed a flattening of the steepest simulated keratometry value (K-max) by an average of 0.74 diopters (D) (P = .004) at 3 months, 0.92 D (P = .002) at 6 months, and 1.45 D (P = .002) at 12 months. A trend toward improvement in best spectacle-corrected visual acuity was also observed. In the control eyes, mean K-max steepened by 0.60 D (P = .041) after 3 months, by 0.60 D (P = .013) after 6 months, and by 1.28 D (P < or = .0001) after 12 months. Best spectacle-corrected visual acuity decreased by logMAR 0.003 (P = .883) over 3 months, 0.056 (P = .092) over 6 months, and 0.12 (P = .036) over 12 months. No statistically significant changes were found for spherical equivalent or endothelial cell density.

Conclusions: Preliminary results of this randomized controlled trial suggest a temporary stabilization of all treated eyes after CXL.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Collagen / metabolism*
  • Corneal Stroma / drug effects*
  • Corneal Stroma / metabolism
  • Corneal Stroma / radiation effects
  • Disease Progression
  • Female
  • Humans
  • Keratoconus / drug therapy*
  • Keratoconus / metabolism
  • Male
  • Microscopy, Confocal
  • Photochemotherapy*
  • Photosensitizing Agents / therapeutic use*
  • Prospective Studies
  • Riboflavin / therapeutic use*
  • Treatment Outcome
  • Ultraviolet Rays
  • Visual Acuity

Substances

  • Photosensitizing Agents
  • Collagen
  • Riboflavin