title: Higher-order aberrations 1 year after corneal collagen crosslinking for keratoconus and their independent effect on visual acuity.
abstract: To evaluate the effect of corneal collagen crosslinking (CXL) in progressive keratoconus patients on higher-order aberrations (HOAs) and the effect of change in HOAs on visual acuity between baseline and 1 year after CXL.
  
  
  
  Tertiary academic referral center, Utrecht, the Netherlands.
  
  
  
  Prospective cohort study.
  
  
  
  This study included consecutive keratoconus patients who were treated with epithelium-off CXL and followed for a minimum of 1 year. The following corneal HOAs were measured with Scheimpflug tomography (Pentacam HR type 70900): coma, trefoil, spherical aberration, and total corneal HOAs. A 2-tailed paired-samples t test was used to compare baseline and postoperative aberrations. Multivariable linear regression was applied to assess the independent effects of HOA subtypes on changes in uncorrected (UDVA) and corrected (CDVA) distance visual acuity.
  
  
  
  Overall, the degree of corneal HOAs in the patient cohort (N = 187) was relatively unchanged after CXL, with a mean change of -1.34% (P = .272). Horizontal coma contributed most to the total amount of HOAs but was virtually unchanged on average. The HOA subtype of spherical aberrations decreased significantly (-15.68%) (P < .001). There was no effect of the change in HOAs on the change in CDVA; however, there was a significant effect of the change in horizontal coma on the change in UDVA (P = .003; B -0.475).
  
  
  
  Corneal HOAs in general were relatively unchanged from baseline to 1 year after CXL in eyes with progressive keratoconus. A change in horizontal coma had a strong and independent effect on UDVA.
  
  
  
  None of the authors has a financial or proprietary interest in any material or method mentioned.
authors: From the Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands. Electronic address: r.p.l.wisse@umcutrecht.nl.
authors: Robert P L
authors: RP
authors: Wisse
authors: From the Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Stijn
authors: S
authors: Gadiot
authors: From the Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Nienke
authors: N
authors: Soeters
authors: From the Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Daniel A
authors: DA
authors: Godefrooij
authors: From the Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Saskia M
authors: SM
authors: Imhof
authors: From the Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Allegonda
authors: A
authors: van der Lelij
mesh_terms: D003094:Collagen / Q000737:chemistry*; D003319:Corneal Stroma; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D006801:Humans; D007640:Keratoconus / Q000628:therapy*; D017319:Photosensitizing Agents; D011446:Prospective Studies; D012256:Riboflavin; D014792:Visual Acuity
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin