Collagen crosslinking with riboflavin and ultraviolet-A light in keratoconus: long-term results

J Cataract Refract Surg. 2008 May;34(5):796-801. doi: 10.1016/j.jcrs.2007.12.039.


Purpose: To prove the long-term dampening effect of riboflavin- and ultraviolet-A-induced collagen crosslinking on progressive keratoconus.

Setting: Department of Ophthalmology, C.G. Carus University Hospital, Dresden, Germany.

Methods: Four hundred eighty eyes of 272 patients with progressive keratoconus were included in this long-term retrospective study. The maximum follow-up was 6 years. At the first and all follow-up examinations, refraction, best corrected visual acuity (BCVA), corneal topography, corneal thickness, and intraocular pressure were recorded.

Results: The analysis included 241 eyes with a minimum follow-up of 6 months. The steepening decreased significantly by 2.68 diopters (D) in the first year, 2.21 D in the second year, and 4.84 D in the third year. The BCVA improved significantly (> or = 1 line) in 53% of 142 eyes in the first year, 57% of 66 eyes in the second year, and 58% of 33 eyes in the first year or remained stable (no lines lost) in 20%, 24%, and 29%, respectively. Two patients had continuous progression of keratoconus and had repeat crosslinking procedures.

Conclusions: Despite the low number of patients with a follow-up longer than 3 years, results indicate long-term stabilization and improvement after collagen crosslinking. Thus, collagen crosslinking is an effective therapeutical option for progressive keratoconus.

MeSH terms

  • Adult
  • Collagen / metabolism*
  • Corneal Stroma / metabolism*
  • Corneal Stroma / radiation effects
  • Disease Progression
  • Follow-Up Studies
  • Humans
  • Keratoconus / drug therapy*
  • Keratoconus / metabolism
  • Photochemotherapy*
  • Photosensitizing Agents / therapeutic use*
  • Retrospective Studies
  • Riboflavin / therapeutic use*
  • Ultraviolet Rays*
  • Visual Acuity


  • Photosensitizing Agents
  • Collagen
  • Riboflavin