Fig. 2

Forest plot of mean differences for the primary and secondary outcomes in randomized clinical trials assessing corneal collagen cross-linking (epi-on vs. epi-off): a standardized mean differences of change in maximum keratometry; b standardized mean differences of change in uncorrected distance visual acuity (UDVA); c standardized mean differences of change in corrected distance visual acuity (CDVA); d standardized mean differences of change in central corneal thickness (CCT); e standardized mean differences of change in endothelial cell density (ECD). The diamond at the bottom of each forest plot shows the result when all the individual studies are combined and averaged. If the outcome of interest favors the epi-on CXL, the diamond is moved to the right of the vertical line; if the outcome of interest favors the epi-off CXL, the diamond is moved to the left of the vertical line