Purpose
To assess the long-term outcomes after corneal cross-linking treatment of progressive keratoconus in pediatric patients.
Methods
Fourty-eight eyes of pediatric patients (mean age 13.7±1.9 years, range 4-18 years) with topographically and tomographically documented progressive keratoconus were treated with cross-linking (CXL). The standard treatment procedure was used, applying riboflavin 0.1% following epithelial abrasion. The corneas were then irradiated with UVA light. The eyes were monitored for a minimum of 24 months. Corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), refraction, topography, tomography and aberrations were documented at 1, 3, 6, 12 and 24 months.
Results
At 24 months after CXL, mean LogMAR UDVA had significantly (p<0.05) improved from 0.81±0.25 to 0.61±0.23. Mean CDVA improved from 0.43±0.14 to 0.21±0.13 (p<0.05). Mean spherical equivalent (SE) refraction had improved from -3.65D±3.49D to -2.14D±2.26D. Accordingly, mean SE refraction showed a significant decrease of 1.51D, in line with the statistically significant reduction of both sphere and cylinder. Topography maps exhibited a statistically significant (p<0.05) reduction of mean simulated keratometry in the flattest meridian from 46.35D to 45.28D, and a near-significant decrease in the steepest meridian from 51.53D to 50.20D. Mean pachymetry, after an initial decrease, recovered by 12 months, and remained stable through the follow-up period. There was a significant (p<0.05) decrease in total, corneal, and higher-order aberrations at 24 months. There was no significant change in endothelial cell counts at any time during the follow-up. Abrasion-related discomfort was reported by most patients in the immediate postoperative period, but there were no significant vision-related adverse effects.
Conclusions
This 2-year follow-up provides further evidence that corneal cross-linking is effective in arresting progressive keratoconus in pediatric patients, the age group that shows the most dramatic progression when left untreated. CXL appears to stabilize keratoconus even long term. The procedure further improves UDVA and CDVA. This improvement is likely due to the significant reduction of corneal asymmetry and corneal as well as total wavefront aberrations.
Keywords: 574 keratoconus •
479 cornea: clinical science