Thinner Corneas Appear to Have More Striking Effects of Corneal Collagen Crosslinking in Patients with Progressive Keratoconus

Purpose. to analyze the outcomes and difference after uva/riboflavin corneal collagen crosslinking (cxl) in four different corneal thickness groups of patients with progressive keratoconus. methods. retrospective study. eyes with progressive keratoconus after cxl were divided into 4 subgroups as follows: group 1,thinnest corneal thickness (tct) ≤ 400 μm; group 2,400 μm < tct ≤ 450 μm; group 3,450 μm < tct ≤ 500 μm; group 4,tct ≥ 500 μm. baseline,6-month,and 12-month visual acuity,corneal topography,tct,and endothelial cell density were evaluated. results. the analysis included 123 eyes of 101 patients. at 6 and 12 months after cxl,there was a mean improvement about visual acuity and keratometry values in all patients. there was a reduction in the change of maximum keratometry (kmax) with the increase of tct. after 1 year of treatment,it was 3.04 ± 0.75 d in group 1,2.38 ± 0.51 d in group 2,1.57 ± 0.35 d in group 3,and 0.31 ± 0.20 d in group 4. conclusion. cxl is successful in halting the progression of keratoconus and there was a negative linear correlation between tct and kmax. advanced cases of progressive keratoconus seemed to obtain more benefits from the flatting effects of cxl. © 2017 yunfei han et al.