Long-term results of riboflavin ultraviolet a corneal collagen cross-linking for keratoconus in Italy: the Siena eye cross study

Am J Ophthalmol. 2010 Apr;149(4):585-93. doi: 10.1016/j.ajo.2009.10.021. Epub 2010 Feb 6.

Abstract

Purpose: To report the long-term results of 44 keratoconic eyes treated by combined riboflavin ultraviolet A collagen cross-linking in the first Italian open, nonrandomized phase II clinical trial, the Siena Eye Cross Study.

Design: Perspective, nonrandomized, open trial.

Methods: After Siena University Institutional Review Board approval, from September 2004 through September 2008, 363 eyes with progressive keratoconus were treated with riboflavin ultraviolet A collagen cross-linking. Forty-four eyes with a minimum follow-up of 48 months (mean, 52.4 months; range, 48 to 60 months) were evaluated before and after surgery. Examinations comprised uncorrected visual acuity, best spectacle-corrected visual acuity, spherical spectacle-corrected visual acuity, endothelial cells count (I Konan, Non Con Robo; Konan Medical, Inc., Hyogo, Japan), optical (Visante OCT; Zeiss, Jena, Germany) and ultrasound (DGH; Pachette, Exton, Pennsylvania, USA) pachymetry, corneal topography and surface aberrometry (CSO EyeTop, Florence, Italy), tomography (Orbscan IIz; Bausch & Lomb Inc., Rochester, New York, USA), posterior segment optical coherence tomography (Stratus OCT; Zeiss, Jena, Germany), and in vivo confocal microscopy (HRT II; Heidelberg Engineering, Rostock, Germany).

Results: Keratoconus stability was detected in 44 eyes after 48 months of minimum follow-up; fellow eyes showed a mean progression of 1.5 diopters in more than 65% after 24 months, then were treated. The mean K value was reduced by a mean of 2 diopters, and coma aberration reduction with corneal symmetry improvement was observed in more than 85%. The mean best spectacle-corrected visual acuity improved by 1.9 Snellen lines, and the uncorrected visual acuity improved by 2.7 Snellen lines.

Conclusions: The results of the Siena Eye Cross Study showed a long-term stability of keratoconus after cross-linking without relevant side effects. The uncorrected visual acuity and best spectacle-corrected visual acuity improvements were supported by clinical, topographic, and wavefront modifications induced by the treatment.

Publication types

  • Clinical Trial, Phase II

MeSH terms

  • Adolescent
  • Adult
  • Cell Count
  • Child
  • Collagen / metabolism*
  • Corneal Stroma / metabolism*
  • Corneal Topography
  • Endothelium, Corneal / pathology
  • Female
  • Follow-Up Studies
  • Humans
  • Italy
  • Keratoconus / drug therapy*
  • Keratoconus / metabolism
  • Keratoconus / physiopathology
  • Male
  • Microscopy, Confocal
  • Photochemotherapy*
  • Photosensitizing Agents / therapeutic use*
  • Prognosis
  • Prospective Studies
  • Riboflavin / therapeutic use*
  • Ultraviolet Rays
  • Visual Acuity / physiology
  • Young Adult

Substances

  • Photosensitizing Agents
  • Collagen
  • Riboflavin