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Updated: Mar 20, 2026
Three Different Protocols of Corneal Collagen Crosslinking in Keratoconus: Conventional, Accelerated and Iontophoresis
Published on: November 12, 2015
Epithelium-on corneal collagen crosslinking for management of advanced keratoconus
Shihao Chen1, Tommy C Y Chan1, Jia Zhang1
1From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China.
Purpose:
To report the 1-year visual and keratometric results of epithelium-on corneal collagen crosslinking (CXL) for advanced keratoconus (median maximum keratometry [K] ≥58.0 diopters [D]).
Setting:
School of Ophthalmology and Optometry and Eye Hospital of Wenzhou Medical College, Wenzhou, China.
Design:
Prospective case series.
Methods:
Patients with bilateral progressive keratoconus had tetracaine-enhanced epithelium-on CXL. The worse eye had CXL, and the fellow eye was not treated. Results were reported 1, 3, 6, and 12 months postoperatively. The outcomes were compared with those in the fellow untreated eyes.
Results:
Twenty-one eyes of 21 patients with a median age of 20.4 years (interquartile range [IQR], 9.5 years) were treated. A significant improvement in postoperative uncorrected distance visual acuity was observed at 12 months (P = .002). Postoperative corrected distance visual acuity improved at 6 months and 12 months (P ≤ .009) compared with baseline values. The maximum K decreased by 1.63 D from the median preoperative maximum K of 62.7 D (IQR, 12.9 D) at 12 months (P < .001). The reduction in maximum K was higher after CXL than in untreated eyes at the end of 12 months (P = .001). Correlation analysis between the preoperative maximum K values and the change over 6 to 12 months between different studies showed a significant correlation (r = -0.764, P < .001; Spearman correlation).
Conclusions:
Epithelium-on CXL was an effective treatment for patients with advanced keratoconus. A higher preoperative maximum K value correlated with greater corneal flattening after CXL.
Financial Disclosure:
None of the authors has a financial or proprietary interest in any material or method mentioned.
