Corneal Biomechanical Properties Changes After Preserved Smile-Derived Concave Lenticule Implantation For Post-Lasik Ectasia

To investigate the long-term changes in corneal biomechanical properties following preserved SMILE-derived concave lenticular implantation for the treatment of cornea ectasia.

Prospective, single-centre, observational study

In this prospective study, nine eyes of 9 patients (32.70±6.99 years) diagnosed with progressive cornea ectasia were treated with SMILE-derived lenticule implantation. All eyes were examined biomechanically (Corvis ST) and tomographically (Pentacam) at baseline, after 1-month, 6-month, and 24-month follow-up. Statistical analysis was performed using Re-ANOVA. Pearson’s correlation was used to identify possible variables correlated with corneal stiffness parameters.

No postoperative complications occurred in all patients during the 2-year follow-up. The mean baseline CCT was 431.50±21.93 µm. The average keratometry was 53.24±3.08 D. Significant increases in CCT and the thinnest point of CCT were observed at each follow-up timepoint compared with baseline(p<0.01). Maximum keratometry values also decreased statistically significantly at 1 month by -1.48 D compared with baseline, which remained relatively stable until the last visit (p<0.01). Biomechanical stiffness parameters, SP-A1 and ARTh, demonstrated significant improvement postoperatively (p<0.05). Conversely, A1/A2 time, length, and velocity did not reach statistical significance postoperatively. SP-A1 was positively correlated to the CCT(p<0.05).

Lenticule implantation could effectively increase the cornea thickness, as well as enhance the corneal biomechanical properties in progressive corneal ectasia patients. The long-term follow-up also validated its long-term stability and safety.