Intraoperative pachymetric measurements during corneal collagen cross-linking with riboflavin and ultraviolet A irradiation.
OBJECTIVE
To study central corneal pachymetric variations during corneal collagen cross-linking (CXL) treatment with the use of riboflavin and ultraviolet A irradiation (UVA).


METHODS
Prospective, noncomparative, interventional clinical study.


METHODS
Fifteen keratoconic patients (19 eyes) were enrolled.


METHODS
All patients underwent riboflavin-UVA-induced corneal CXL. Intraoperative central corneal thickness (CCT) measurements using ultrasound pachymetry were performed during the procedure. Measurements were obtained after epithelial removal, after riboflavin drop instillation, and every 5 minutes (6 interval times) during UVA irradiation (30 minutes).


METHODS
Central corneal thickness measurements.


RESULTS
Mean patient age was 26.9+/-6.5 years (range, 17-40 years). Ten were male and 5 were female. Mean preoperative CCT was 458.5+/-21.5 microm (range, 427-494 microm; 95% confidence interval [CI], 448-467 microm) and 415.7+/-20.6 microm (range, 400-468 microm; 95% CI, 406-426 microm) before and after epithelial removal, respectively. There was a statistically significant decrease (mean, 75 microm) of CCT between the epithelial removal interval (415.7+/-20.6 microm; range, 400-468 microm) and at the end of riboflavin solution instillation (340.7+/-22.9 microm; range, 292-386 microm; P<0.001). There was no statistically significant change in CCT during irradiation (P>0.05). There was no statistically significant difference between preoperative and 1-month postoperative endothelial cell count (preoperative, 2780+/-197 to 1-month postoperative, 2713+/-116; P = 0.14). No intraoperative, early postoperative, or late postoperative complications were observed in this patient series.


CONCLUSIONS
During corneal CXL with the use of riboflavin and UVA irradiation, a statistically significant decrease of CCT was demonstrated.
Kymionis
George D
GD
Institute of Vision and Optics University of Crete, Heraklion, Crete, Greece.
Kounis
George A
GA
Portaliou
Dimitra M
DM
Grentzelos
Michael A
MA
Karavitaki
Alexandra E
AE
Coskunseven
Efekan
E
Jankov
Mirko R
MR
Pallikaris
Ioannis G
IG
D000293:Adolescent; D000328:Adult; D001837:Body Weights and Measures; D003094:Collagen / Q000378:metabolism*; D003315:Cornea / Q000000981:diagnostic imaging*; D003319:Corneal Stroma / Q000378:metabolism; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D007640:Keratoconus / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D012256:Riboflavin / Q000627:therapeutic use*; D014463:Ultrasonography; D014466:Ultraviolet Rays
D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin