Visual recovery after corneal crosslinking for keratoconus: a 1-year follow-up study.
OBJECTIVE
To evaluate visual recovery and intraocular straylight in keratoconus patients 3 months and 1 year after corneal crosslinking (CXL) PATIENTS AND METHODS: Thirty-three eyes of 28 consecutive patients with mild to moderate keratoconus were included. The following were assessed at baseline, 3 months and 1 year after CXL: corrected distance visual acuity (CDVA), intraocular straylight, spherical equivalent (SE), keratometry (Kmax and K min (Diopters D and axis), the regularity index and pachymetry. Changes from baseline were calculated using mixed linear regression models.


RESULTS
The CDVA remained unchanged 3 months after CXL (-0.003 (95 % CI: -0.038 to 0.044); p = 0.880) and improved after 1 year (-0.042 (95 % CI: -0.078 to -0.007; p = 0.021)). The mean straylight value increased significantly by 0.27 (95 % CI: 0.18 to 0.35; p < 0.001) 3 months after CX and normalized to preoperative values after 1 year (0.06 (95 % CI: -0.03 to 0.14; p = 0.215)). SE improved from the mean preoperative value of -2.61 D (95 % CI: -3.83 to -1.39) by 1.95 (95 % CI: 1.03 to 2.86; p < 0.001) at 3 months and remained stable at the 1-year follow-up visit (2.17 (95 % CI: 1.21 to 3.12; p < 0.001)). Parameters of of keratometry changed only minimally. The regularity index remained almost unchanged at 3 months (2.45 (95 % CI: -4.97 to 9.88; p = 0.503)) and decreased by 6.97 (95 % CI: -14.08 to 0.14; p = 0.054). Pachymetry decreased by 44.0 μm (95 % CI: 56.1 to 31.9; p < 0.001) at 3 months and almost returned to preoperative values at 12 months (-11.3 μm (95 % CI: -27.9 to 5.3; p = 0.175)).


CONCLUSIONS
In accordance with the decrease in CDVA and patients' complaints of disability due to glare, intraocular straylight increased 3 months after surgery. One year after CXL, there was an increase in CDVA due to an improved SE and regularity index, and intraocular straylight had normalized.
Eye Clinic, Cantonal Hospital of Lucerne, Lucerne, Switzerland. Ivo.Guber@ksw.ch
Ivo
I
Guber
Josef
J
Guber
Claude
C
Kaufmann
Lucas M
LM
Bachmann
Michael A
MA
Thiel
D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000378:metabolism; D003315:Cornea / Q000502:physiology*; D003319:Corneal Stroma / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D005260:Female; D019466:Glare; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008027:Light; D008297:Male; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology; D012256:Riboflavin / Q000627:therapeutic use; D012542:Scattering, Radiation; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult
D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin