OBJECTIVE: To investigate the effect of standard and accelerated corneal collagen cross-linking (CXL) in keratoconus and compare the merits and drawbacks. STUDY DESIGN: Clinical data of 70 keratoconus patients after CXL were retrospectively analyzed, and they were divided into standard group (n=32) and accelerated group (n=38) according to the method of CXL. Vision changes (uncorrected visual acuity [UCVA], best corrected visual acuity [BCVA], spherical equivalent [SE]), corneal morphology (maximum keratometry [Km], central corneal thickness [CCT]), corneal endothelial cells (endothelial cell density [ECD], coefficient variation of cell size [CV], percentage of hexagonal corneal cells [Hex]), and adverse reactions of the 2 groups were compared. RESULTS: As compared with standard CXL, the corneal epithelium was retained and the intensity of ultraviolet radiation was increased (the total radiation energy remained unchanged) in accelerated CXL. Both standard and accelerated CXL could well improve UCVA and SE, thanks to the retention of the corneal epithelium. In the short term after operation, Km and CCT of accelerated CXL were improved, and the density and morphology of endothelial cells were relatively better (p<0.05). Moreover, the above results reflected that increasing of ultraviolet radiation intensity did not aggravate the damage of endothelial cells. However, in the long-term, the corneal morphology and endothelial cells of standard CXL were significantly improved. In terms of adverse reactions, the incidence of haze in standard CXL was significantly increased (p<0.05), and the incidence of delayed corneal epithelium healing and corneal infection were relatively higher than those of accelerated CXL (p>0.05). CONCLUSION: Standard and accelerated CXL could both effectively inhibit the progression of keratoconus; in addition, accelerated CXL could significantly shorten the treatment time and better protect the density and morphology of corneal endothelial cells, and its safety was relatively better. © Science Printers and Publishers, Inc.