This retrospective review found 2 factors that may help identify children at risk of keratoconus progression 2 years after corneal collagen crosslinking (CXL) treatment.
Patients with paracentrally located cones (K-max outside of the central 3 mm zone but within a 5 mm zone, P=0.023) or a baseline thinnest corneal thickness of less than 450 µm microns (P=0.008) had a higher risk of progression 2 years after treatment.
If left untreated, the progression rate of keratoconus in children is a staggering 88%. That’s why an international panel of keratoconus experts, the Delphi panel, recently agreed that CXL should be performed in pediatric patients with keratoconus with or without progression of the disease.
But which patients are more likely to have successful outcomes? This study helps further define the characteristics predictive of success, and it may help identify different treatment paradigms for patients with a higher risk of progression.
The authors analyzed 52 consecutive patients (72 eyes) age 18 or younger who underwent CXL and were followed for 2 years. Demographic, visual and topographic preoperative properties were assessed. Progression was defined as >=1 D increase in K-max 2 years after CXL treatment.
Mean UCVA significantly improved and the mean corneal thickness at the thinnest point (thCT) significantly decreased in all patients (P=0.023, P<0.001, respectively).
As previously reported, preoperative corneal thickness at the thinnest point (thCT) was a significant factor affecting progression. The progression rate of K-max was 47.6% in eyes with preoperative thCT thinner than 450 µm, and was nearly 3 times higher than the thicker corneas. Cone location was also a risk factor, with 23.8% of eyes with centrally located cones and 50% of eyes with paracentrally located cones showing progression at 2 years after CXL.
Age, sex, baseline UCVA, CDVA and K-max appeared to have no significant effect on progression.
This study’s chief drawback is the relatively short follow up of only 2 years, which may underestimate progression in this young patient population which faces a lifetime risk of progression. Alternatively, initial K-max steepening may result even from effective CXL, despite overall long-term stability.