Comparison of pulsed and continuous accelerated corneal crosslinking for keratoconus: 1-year results at a single center.

PURPOSE: To compare the clinical outcomes between pulsed and continuous accelerated crosslinking (CXL) for keratoconus.

SETTING

Hospital.

DESIGN

Retrospective comparison study.

METHODS

Korean patients who were treated for keratoconus between September 2015 and January 2018 at Seoul St. Mary's Hospital were included. Eyes were subjected to pulsed accelerated crosslinking (30 mW/cm2 for 8 minutes, 1 second on/1 second off) or continuous accelerated crosslinking (30 mW/cm2 for 4 minutes; delivering 7.2 J/cm2). Outcomes were evaluated after 1 year.

RESULTS

At 1 year, the 2 groups did not exhibit changes in their corrected and uncorrected distance visual acuity values. The pulsed group (25 eyes in 25 patients) exhibited significantly improved values for sphere (P = .009) and spherical equivalent (P = .033), although no statistically significant difference was observed in the continuous group (20 eyes in 20 patients). All keratometry (k)values (SimKf, SimKs, SimKmean, and Kmax) improved in both groups (all P < .05), although the pulsed group had significantly greater changes in the SimKmean value (P = .036) and the Kmax value (P = .03). Both groups had significantly decreased central and thinnest corneal thicknesses (all P < .001), although the pulsed group had a substantially lower thinnest corneal thickness (P = .017). Corneal densitometry measured using the Pentacam device increased in both groups (all P < .001), with a higher densitometry value in the pulsed group (P = .013). Furthermore, the depth of the demarcation line was deeper in the pulsed group (P = .015).

CONCLUSIONS

Pulsed accelerated crosslinking might provide better postcrosslinking effects than continuous accelerated crosslinking.