Intraoperative and postoperative effects of corneal collagen cross-linking on progressive keratoconus.
OBJECTIVE
To report intraoperative and 24-month refractive, topographic, tomographic, and aberrometric outcomes after corneal collagen cross-linking in progressive advanced keratoconus.


METHODS
Prospective, nonrandomized single-center clinical study involving 28 eyes. Main outcome measures included uncorrected and best spectacle-corrected visual acuities, sphere and cylinder refraction, topography, tomography, aberrometry, and endothelial cell count evaluated at baseline and follow-up at 1, 3, 6, 12, and 24 months after treatment. Topography was also recorded intraoperatively.


RESULTS
Two years after treatment, mean baseline uncorrected and best spectacle-corrected visual acuities improved significantly (P = .048 and <.001, respectively) and mean spherical equivalent refraction decreased significantly (P = .03). Mean baseline flattest and steepest meridians on simulated keratometry, simulated keratometry average, mean average pupillary power, and apical keratometry all decreased significantly (P < .03). Deterioration of the Klyce indices was observed in the untreated contralateral eyes but not in treated eyes. Total corneal wavefront aberrations Z(0) (piston), Z(2) (defocus), and Z(7) (III coma) decreased significantly (P < or = .046). Mean 12-month baseline pupil center pachymetry and total corneal volume decreased significantly (P = .045). Endothelial cell counts did not change significantly (P = .13).


CONCLUSIONS
Two years postoperatively, corneal collagen cross-linking appears to be effective in improving uncorrected and best spectacle-corrected visual acuities in eyes with progressive keratoconus by significantly reducing corneal average pupillary power, apical keratometry, and total corneal wavefront aberrations.
Vinciguerra
Paolo
P
Department of Ophthalmology, Istituto Clinico Humanitas, Via Manzoni 56, Rozzano 20089, Milan, Italy.
Albè
Elena
E
Trazza
Silvia
S
Seiler
Theo
T
Epstein
Daniel
D
D000328:Adult; D002452:Cell Count; D003094:Collagen / Q000378:metabolism*; D003319:Corneal Stroma / Q000378:metabolism*; D019781:Corneal Topography; D018450:Disease Progression; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007432:Intraoperative Period; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011184:Postoperative Period; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology*; D012256:Riboflavin / Q000627:therapeutic use; D016896:Treatment Outcome; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology*
D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin