Purpose: To report the long-term outcome of corneal collagen cross-linking (CXL) for progressive keratoconus in pediatric patients.
Methods: “Epithelium-off” CXL was performed in pediatric eyes with progressive keratoconus. Spectacle-corrected distance visual acuity (CDVA), retinoscopy, topography, and tomography were documented preoperatively and postoperatively at 3 months, 6 months, 1 year, and annually thereafter.
Results: A total of 377 eyes of 336 pediatric patients aged 8 to 18 years with progressive keratoconus underwent CXL. Of these, 194 eyes had a follow-up beyond 2 years and up to 6.7 years. At last follow-up, there was significant improvement in mean CDVA from 0.33 ± 0.22 to 0.27 ± 0.19 logMAR (P ≤ 0.0001), reduction in mean topographic astigmatism from 7.22 ± 3.55 to 6.13 ± 3.28 D (P = 0.0001), mean flattening of 1.20 ± 3.55 diopters in maximum keratometry (Kmax) (P = 0.0002), and mean corneal thinning of 31.1 ± 36.0 μm (P < 0.0001) after CXL. The mean change in Kmax was most significant in moderately advanced keratoconus (average keratometry 48–53 diopters). Central cones showed more corneal flattening than peripheral cones. Stabilization or flattening of Kmax was seen in 85% of eyes at 2 years and in 76% after 4 years. Stabilization or improvement of CDVA was seen in 80.1% of eyes at 2 years and in 69.1% after 4 years.
Conclusions: CXL remains effective in stabilizing keratoconus for longer than 2 years in a majority of pediatric eyes. Flattening of Kmax was greater in moderately advanced keratoconus and central cones. Long-term follow-up beyond 4 years, however, revealed that a few eyes showed features suggestive of reversal of the effect of CXL.
Department of Cornea and Refractive Surgery, Medical Research Foundation, Sankara Nethralaya, Chennai, India.
Reprints: Prema Padmanabhan, MS Ophthal, Medical Research Foundation, Sankara Nethralaya, 41, College Rd, Chennai 600 006, India (e-mail: firstname.lastname@example.org).
The authors have no funding or conflicts of interest to disclose.
Received February 08, 2016
Received in revised form July 16, 2016
Accepted October 18, 2016