Evaluation of the shifting of the line of sight and higher order aberrations of eyes with keratoconus after corneal cross-linking.
OBJECTIVE
To evaluate changes in the coordinates of the line of sight (LoS) and higher order aberrations (HOAs) of eyes with keratoconus, following corneal cross-linking (CXL).


METHODS
All patients (93 eyes) underwent detailed ophthalmologic examination and Pentacam HR measurements at baseline and at 3, 6, and 12 months after corneal CXL. LoS coordinates on the horizontal (x) and vertical (y) axes, vertical coma, vertical trefoil, spherical aberration, total root-mean square (RMS), and HOA-RMS values were recorded along with visual acuity and topographical parameters.


RESULTS
LoS significantly shifted to the nasal region after corneal CXL in both right and left eyes (p=0.003 and p=0.01, respectively). Horizontal axis values of both eyes significantly shifted to the temporal region at postoperative 6th months compared to the baseline measurements (p=0.02 and p=0.02, respectively) and remained the same between postoperative 6th months and 12th months (p=1.00 and p=0.97, respectively). Total-RMS, HOA-RMS, vertical coma, and spherical aberration values significantly improved after corneal CXL (p<0.001, p=0.02, p=0.04, and p<0.001, respectively). The improvements in HOAs were significant at postoperative 6th months compared to the baseline measurements (p=0.003, p=0.02, p<0.001, and p=0.003, respectively) while remained the same between postoperative 6th months and 12th months (p>0.05 for all values). The changes in horizontal-axis coordinates in left eyes were significantly correlated with anterior elevation, anterior astigmatism, total-RMS and HOA-RMS changes (r2=0.20, p=0.03; r2=0.35, p<0.01; r2=0.50, p<0.001 and r2=0.35, p=0.004; respectively).


CONCLUSIONS
LoS significantly shifted to the nasal region and HOAs improved after corneal CXL and these changes stabilized 6th months after corneal CXL. It would be more better to perform refractive surgery in crosslinked corneas at least 6th months after corneal CXL.
Ulucanlar Eye Training and Research Hospital, Ankara, Turkey. Electronic address: drkosekahya2@gmail.com.
Pinar
P
Kosekahya
Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
Mustafa
M
Koc
Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
Kemal
K
Tekin
Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
Murat
M
Uzel
Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
Cemile Ucgul
CU
Atilgan
Mardin State Hospital, Department of Ophthalmology, Mardin, Turkey.
Mehtap
M
Caglayan
Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
Pelin
P
Yilmazbas
D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000503:physiopathology; D002648:Child; D003094:Collagen / Q000378:metabolism; D003319:Corneal Stroma / Q000378:metabolism*; D019781:Corneal Topography; D057108:Corneal Wavefront Aberration / Q000503:physiopathology*; D003432:Cross-Linking Reagents; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D012189:Retrospective Studies; D012256:Riboflavin / Q000627:therapeutic use; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult
D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin
Corneal cross-linking; Higher order aberrations; Line of sight