Clinical effect of corneal collagen cross-linking for keratoconus in teenagers

Objective To evaluate the safety and efficacy of epithelium-off corneal collagen cross-linking (CXL) induced by riboflavin and ultraviolet A light for keratoconus in teenagers. Methods The medical records of consecutive patients (30 eyes of 19 cases) at the age of 14-18 years treated with epithelium-off CXL for keratoconus were analyzed in this retrospective self-control study. Data from preperative and 3-, 6-, and 12-month postoperative examinations were analyzed by one way repeated ANOVA. The clinical evaluations included uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), maximum keratometry (Kmax), thinnest corneal thickness (TCT), and endothelial cell density (ECD). Results UCVA measured as the log of the minimum angle of resolution (LogMAR) was 0.78±0.33 at baseline before surgery and 0.77±0.34,0.72±0.33, and 0.67±0.31 at 3-, 6-, and 12-months after surgery. There was significant improvement of UCVA at 12 months compared to the baseline (P<0.001). LogMAR BCVA increased from 0.42±0.33 to 0.29±0.23 and 0.23±0.20 at 6- and 12-months after surgery (both P<0.05). The Kmax value was 62.1±11.3 diopter (D) before treatment and improved significantlyto 60.4±9.9 D and 59.9±9.5 D at 6 and 12 months after treatment respectively. The preoperative TCT was 446±41 μm and thinned to 430±39 μm at 12 months after surgery (P<0.001). There were no significant differences between the preoperative and 12-month postoperative ECD. No complications occurred in the overall group throughout the study period. Conclusion Epithelium-off CXL is safe and effective in treating teenage keratoconus. The procedure improved the visual acuity and keratometry values at 12 months after surgery. Key words: Teenagers; Keratoconus; Corneal collagen cross-linking; Therapy outcomes