The Dresden protocol of 3mW/cm2 irradiance for 30 minutes has been extensively studied and has shown advantageous clinical and topographical results. However, this protocol is time-consuming and therefore accelerated CXL using higher irradiance to shorten treatment duration has emerged. The aim of this retrospective comparative interventional study was to compare the effect of conventional corneal collagen cross-linking (CXL) (3mW/cm2, 30 min) with accelerated CXL (9mW/cm2, 10 min) for the treatment of progressive keratoconus. Fourteen eyes were included in the conventional group and 12 eyes were included in the accelerated group. The average follow-up time was 13.9±6.3 months (median 12 months). There were no significant differences in the baseline parameters between the two groups. In conventional CXL, corrected distance visual acuity (CDVA) significantly improved and there was also a significant reduction in Kmax and Kmean. In the accelerated CXL group, there was no significant change in CDVA, Kmax and Kmean postoperatively. In conclusion, both conventional and accelerated CXL were effective in stabilising keratoconus progression after 12 months. Significant improvements in CDVA and corneal flattening was demonstrated following conventional CXL, but not with accelerated CXL.