AIM:To investigate the clinical efficacy and safety of trans-epithelial accelerated corneal collagen cross-linking in the treatment of progressive keratoconus.

METHODS: A prospective before-after self-control study. A total of 47 eyes of 37 patients with progressive keratoconus who underwent trans-epithelial accelerated corneal collagen cross-linking in our hospital from August 2016 to November 2019 were collected. Uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), refractive status, corneal transparency, maximum keratometry value of the anterior corneal surface, thinnest corneal thickness, corneal endothelial cell counts and intraocular pressure(IOP)were analysed preoperatively and at 1, 3, 6 and 12mo postoperative.

RESULTS: UCVA of patients 1, 3, 6 and 12mo after surgery was higher than that before surgery, but there was no difference(F=1.372, P=0.261). BCVA at 1, 3, 6 and 12mo after surgery was higher than that before surgery, the difference was statistically significant(F=3.308, P=0.019). There were no differences in the spherical and cylindrical power, Kmax and thickness of the thinnest point of cornea at 1, 3, 6 and 12mo postoperatively compared with those before surgery(F=0.293, 1.378, 2.448, 1.970; P=0.881, 0.258, 0.061, 0.116). There was no difference in corneal endothelial cell counts between 1mo after surgery and before surgery(t=1.156, P=0.25). There was no difference in IOP at all postoperative time points compared with that before surgery(F=1.221, P=0.321). The corneal Haze(grade 1-2)appeared in 7 eyes after surgery, and subsided in 5 eyes from 3-6mo after surgery, and the corneal transparency recovered. The corneal nebula remained in 1 eye, and the corneal central stroma linear opacity existed in 1 eye, but the visual acuity of both eyes was not affected.

CONCLUSION: Trans-epithelial accelerated corneal collagen cross-linking can significantly improve BCVA, stabilize refractive status, corneal morphology and thickness, prevent or delay the progression of keratoconus, and enable patients to obtain better visual function. At the same time, the operation time is short, postoperative complications are less, and the operation has good safety.