Purpose:
To study the effect of Riboflavin and ultraviolet A induced collagen cross linking (CXL) in post-LASIK ectasia .

Subjects and Methods:
Twenty eyes of seventeen patients undergoing collagen cross-linking, measurements at 1, 3,6, 12 and 24 months after corneal cross linking were: Best corrected visual acuity (BCVA), slit lamp examination, the Oculyzer for detecting K readings, corneal thickness, and anterior and posterior elevations maps.

Results:
There was significant improvement of BCVA and K readings at two years postoperatively. The mean BCVA improved from 0.4 ± 0.25 to 0.64 ± 0.21(P