Comparison Of Corneal Biomechanical Changes After Lasik And Femto-Smile With Corvis St

To evaluate changes in corneal biomechanics after LASIK and Femto-SMILE.

Elite Center, Tanta, Egypt. 

Design: Prospective, non-randomized, unmasked, interventional comparative case series.

60 eyes, candidates for refractive surgery, were equally divided into two groups; Group A: received LASIK and group B: received Femto-SMILE. Pentacam and CorVis ST parameters were compared before and 6 months after procedures. P≤0.05 was used for significance of results. 

IOPb decreased in group A (P=0.092), and in group B (P<0.001) and difference between groups became significant (P=0.001). DA increased significantly, but difference between groups remained insignificant (P=0.461). IR increased significantly in Group A and and the postoperative difference was significant (P 0.026). ARTH decreased insignificantly and the difference remained insignificant (P=0.928). SP-A1 decreased in group A (P=0.637), and in group B (P<0.001) and the postoperative difference was significant (P=0.013). CBI increased significantly in group A (P<0.001) and postoperative difference was highly significant (P<0.001). A significant correlation was found between changes in CCT and  DA, IR and ARTH after surgery in both groups. 

The significant differences between groups postoperatively as regards IOPb (P=0.001), IR (P=0.026), SP-A1 (P=0.013) and CBI (P<0.001) indicate stiffer corneas after Femto-SMILE and suggest less influence on corneal biomechanics than LASIK.