Corneal cross-linking in pediatric patients: Evaluating treated and untreated eyes—5-year follow-up results

Purpose: To evaluate the long-term results of corneal collagen cross-linking (CXL) for treatment of pediatric keratoconus and the long-term outcomes of the fellow untreated keratoconic eye in patients younger than 18 years old. Methods: A retrospective case analysis was performed on 88 eyes of 44 patients aged 18 years or younger, with keratoconus, who underwent CXL in at least 1 eye. Follow-up measurements, for the treated and untreated eye pair, taken up to 5 years after treatment, were compared with baseline values. Parameters included uncorrected distance visual acuity (UCDVA), best spectacle-corrected distance visual acuity (BCDVA), manifest refraction, pachymetry, and corneal topography and tomography. Results: Mean age of patients was 15.6 6 2.1 years. For the treated eyes, during all years of follow-up, UCDVA improved significantly (from 0.83 6 0.30 to 0.72 6 0.28 logMAR; P = 0.01). Improvement in BCDVA was not statistically significant (from 0.28 6 0.19 to 0.23 6 0.15 logMAR; P = 0.06). The manifest cylinder showed a significant reduction (from 5.8 6 3.6 to 4.3 6 2.5 diopters; P = 0.006). There was no significant change in maximum keratometry. Average keratometry and corneal thickness reduced significantly (P = 0.009 and P = 0.002, respectively). Five patients had very mild corneal haze after CXL. For the fellow untreated eyes—during 5 years of followup, UCDVA showed a slight decrease that was not statistically significant. BCDVA, average keratometry, and maximum keratometry remained stable. Conclusions: Our long-term follow-up study suggests that CXL is a safe procedure in the pediatric age, and there is no urgency in treating pediatric patients with keratoconus without proof of progression.