Corneal crosslinking for keratoconus in children with thin corneas: A multicentre registry study

Purpose

This study reports the clinical outcomes of corneal crosslinking in children with thin corneas in the real-world setting.

Design

Retrospective, longitudinal study

Subjects

The subjects were extracted from the Save Sight Keratoconus Registry and 18 children (21 eyes) under the age of 18 with corneas of 400 µm or less were included in the study.

Methods

Using the Save Sight Keratoconus Registry data was collected from 10 practices across Australia and New Zealand. Outcomes were assessed at the final follow-up visit. The primary outcome measure was a change in corneal curvature. Secondary outcomes included a change in visual acuity, a change in corneal thickness, and adverse events.

Results

Eighteen patients (21 eyes), of which 12 (66.7 %) were male, with a median age of 16 years (IQR 4.0, Range 8 to 18) underwent CXL. Median follow-up was 10 months (IQR 8, range 3 -55). Median values in outcome measures changed from baseline to follow-up: Kmax from 70.5D (IQR 15.5) to 69.3D (IQR 20.7), K2 from 60.5D (IQR 11.3) to 58.6D (IQR 13.5), habitual visual acuity from 47 (IQR 44.0) to 50 (IQR 31.0) LogMAR letters, pinhole visual acuity from 55 (IQR 11.0) to 60 (IQR 11.0) LogMAR letters and minimum corneal thickness from 390 μm (IQR 29.0) to 370.5 μm (IQR 48.5). Three eyes experienced adverse events. Two developed corneal scarring and one developed microbial keratitis requiring corneal graft.

Conclusions

This real-world study shows that CXL in children with thin corneas can stabilise corneal parameters and vision. Adverse events occur and include scarring and microbial keratitis. The small sample size and short duration of follow-up are notable limitations, and further larger prospective studies are needed to determine the safety and efficacy of CXL in children.