Selection of the method for additional correction of ametropia after previous femtosecond laser lenticule correction of myopia and myopic astigmatism using CLEAR technique

Objective. The study presents 3 options for additional correction of ametropia after previous femtosecond laser correction of myopia and myopic astigmatism using the corneal lenticule extraction for advance refractive correction (CLEAR) technique. Material and methods. The study included 3 patients (3 eyes). After CLEAR surgery, patient 1 had uncorrected visual acuity (UCVA) in the left eye (OS) of 0.8 with correction sph (+)0.25 cyl (+)1.0ax113=1.0; in patient 2 UCVA OS was 0.4 with correction sph (–)1.25 cyl (–)0.25ax134=1.0; in patient 3 UCVA OS was 0.4 with correction cyl (–)1.75–42=1.0. In the first case, the corneal flap was created mechanically, in the second case, a 3D corneal flap edge was created using the Femto Z8 femtosecond laser system, and in the third case, a 2D corneal flap edge was created using the same system. Excimer laser ablation of residual ametropia was then performed in all cases. Results. The surgeries were completed without complications. UCVA of 1.0 was achieved in all cases. Conclusion. Post-CLEAR ametropia correction is possible by shaping the edge of the corneal flap using a mechanical method, as well as using the Femto Z8 femtosecond laser system with the “side-cut-only” and “border-cut-only” programs.