Higher-order aberrations after corneal collagen crosslinking for keratoconus and corneal ectasia

J Cataract Refract Surg. 2012 Feb;38(2):292-302. doi: 10.1016/j.jcrs.2011.08.041.

Abstract

Purpose: To determine changes in higher-order aberrations (HOAs) after corneal collagen crosslinking (CXL).

Setting: Cornea and refractive surgery practice.

Design: Prospective randomized controlled clinical trial.

Methods: Corneal and ocular HOAs were measured and analyzed using the Pentacam device and Ladarwave aberrometer, respectively, at baseline and 12 months after CXL.

Results: Ninety-six eyes (64 keratoconus, 32 ectasia) of 73 patients had CXL. A fellow-eye control group comprised 42 eyes. The mean preoperative total anterior corneal HOAs, total coma, 3rd-order coma, and vertical coma were 4.68 μm ± 2.33 (SD), 4.40 ± 2.32 μm, 4.36 ± 2.30 μm, and 4.04 ± 2.27 μm, respectively. At 1 year, the mean values decreased significantly to 4.27 ± 2.25 μm, 4.01 ± 2.29 μm, 3.96 ± 2.27 μm, and 3.66 ± 2.22 μm, respectively (all P<.001). There were no significant changes in posterior corneal HOAs. The mean preoperative total ocular HOAs, total coma, 3rd-order coma, trefoil, and spherical aberration were 2.80 ± 1.0 μm, 2.60 ± 1.03 μm, 2.57 ± 1.03 μm, 0.98 ± 0.46 μm, and 0.90 ± 0.42 μm, respectively. At 1 year, the mean values decreased significantly to 2.59 ± 1.06 μm, 2.42 ± 1.07 μm, 2.39 ± 1.07 μm, 0.88 ± 0.49 μm, and 0.83 ± 0.38 μm, respectively (all P=.01). After CXL, HOAs were significantly improved compared with the control group. Changes in HOAs were not statistically associated with an improvement in visual acuity or most subjective visual symptoms, however.

Conclusion: Corneal and ocular HOAs decreased after CXL, suggesting an improvement in corneal shape.

Publication types

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

MeSH terms

  • Aberrometry
  • Adolescent
  • Adult
  • Collagen / metabolism*
  • Corneal Stroma / drug effects*
  • Corneal Stroma / metabolism
  • Corneal Topography
  • Corneal Wavefront Aberration / physiopathology*
  • Cross-Linking Reagents*
  • Dilatation, Pathologic / drug therapy
  • Dilatation, Pathologic / etiology
  • Dilatation, Pathologic / metabolism
  • Dilatation, Pathologic / physiopathology
  • Humans
  • Keratoconus / drug therapy*
  • Keratoconus / etiology
  • Keratoconus / metabolism
  • Keratoconus / physiopathology
  • Keratomileusis, Laser In Situ
  • Photosensitizing Agents / therapeutic use*
  • Postoperative Complications
  • Prospective Studies
  • Riboflavin / therapeutic use
  • Surveys and Questionnaires
  • Ultraviolet Rays
  • Visual Acuity / physiology

Substances

  • Cross-Linking Reagents
  • Photosensitizing Agents
  • Collagen
  • Riboflavin