Should physicians stratify CXL waiting time by age?

Investigators of this observational study examined topographical changes in patients with keratoconus while awaiting corneal crosslinking (CXL) treatment.

Study design

The prospective study included 104 patients diagnosed with keratoconus. Progression was defined as a change in the curvature within the cone area of at least 1 D on tangential map and a thinning of 20 μm at the thinnest point.

Outcomes

On average, patients waited for 84.8 days from the time of diagnosis to CXL treatment. During the waiting period, approximately one-quarter showed evidence of progression.

Patients who progressed while waiting for treatment were younger than those who did not progress (22.2 vs. 25.4 years; P=0.02). Stratification by age groups showed a significant worsening of maximum keratometry in patients younger than 18 years compared with patients aged 18 to 26 years, or those older than 26 years (P=0.002 and 0.042, respectively).

Limitations

The study did not include participants older than 40 years, which would have been an interesting comparison since keratoconus progression is influenced by age-related corneal stiffening process.

Clinical significance

Younger patients with keratoconus should be treated sooner to avoid further progression of keratoconus. The multivariate model confirmed that steepening of the maximum keratometry while waiting for treatment was associated with age.