Corneal collagen crosslinking (CXL) is quickly becoming the standard to halt keratoconus progression, and new approaches that attempt to speed up healing time and provide better visual outcomes are showing promising results.

A recent study published in the American Journal of Ophthalmology reports accelerated pulsed CXL was safe, effective and provided a neutrally refractive intervention in halting keratoconus progression at two years.

The investigation enrolled 870 patients (1,192 eyes) that underwent CXL at the Moorfields Eye Hospital in the UK. All patients had progressive keratoconus. Corneas with a minimum stromal thickness of less than 375μm were excluded. The procedure included a riboflavin 0.1% soak duration of 10 minutes and high-fluence pulsed UVA delivered at 30mW/cm2 for four minutes, with a 1.5 second on/off cycle (total energy 7.2 J/cm2).

The researchers performed subjective refraction, corneal tomography and specular microscopy at baseline and six, 12 and 24 months postoperatively. The study’s primary outcome measure was a change in maximum keratometry (Kmax) at 24 months. Follow-up data was available for 543 patients at 12 months and 213 subjects at 24 months, and patients were approximately 25 years old. 

In mild cones (Kmax <55D), keratometry remained unchanged at 24 months. However, in more advanced disease, the researchers observed modest corneal flattening compared with baseline (Kmax 63.2±6.5D vs. 61.9 ± 8.1D), but no significant changes were seen in central keratometry.

Keratoconuse stabilization was confirmed in 98.3% of eyes, and no changes were seen in mean corrected distance visual acuity, manifest refraction and endothelial cell density. Only 2.7% of eyes lost more than two lines of corrected distance visual acuity, the researchers noted.

Gore DM, Leucci MT, Koay S, et al. Accelerated pulsed high-fluence corneal cross-linking for progressive keratoconus. American Journal of Ophthalmology. August 18, 2020. [Epub ahead of print].