PURPOSE: To compare refractive, topographic, pachymetric and corneal biomechanical outcomes of Riboflavin-UVA collagen cross-linking (CXL) on ectatic corneas for up to12 months of follow up.METHODS: A Prospective Interventional study where thirty-five eyes of 18 patients all underwent corneal collagen cross-linking using Riboflavin and Ultraviolet-A. Inclusion criteria were patients 13-45 years of age with progressive keratoconus or post-LASIK ectasia .Patients’ corneas should have a clear centre with minimum thickness of 400 μm and a topographic mean K value less than 60 D. Uncorrected visual acuity, best spectacle-corrected visual acuity, pentacam and ORA results were evaluated at baseline and at 2, 6 and 12 months postoperatively and compared pre- and post-operatively.RESULTS: The study revealed a statistically signicifant improvement in both the final UCVA (p ≤ 0.04) and BSCVA(p ≤ 0.001) by the end of the study. There was also a significant improvement in all 3 topographic parameters (p ≤ 0.05) yet no significant changes in pachymetry. The index of vertical asymmetry was significantly better (p ≤ 0.05) denoting improvement in corneal symmetry. No significant improvement in CH or CRF was encountered at all.CONCLUSIONS: Corneal CXL treatment is a relatively new, revolutionary, minimally invasive procedure aiming at the stabilization of corneal ectatic disorders. CXL treatment was proven to halt keratoconus progression, with astatistically significant improvement in visual and topographic parameters. From our results we found that one year postoperatively, corneal collagen cross-linking appears to be effective in improving uncorrected and best spectacle-corrected visual acuities in eyes with progressive ectasia by causing significant refractive, topographic and clinical modifications. We believe that collagen cross-linking should become a standard treatment for progressive ectasia whether pathogenetic or iatrogenic. A combination of CXL with any other procedure comes next and should be tailored according to each patient.