Impact of ablation ratio on 5-year postoperative posterior corneal stability after refractive surgery: SMILE and FS-LASIK.

Ablation ratio was strongly correlated with postoperative posterior corneal elevation in a 5-year follow-up in both SMILE and FS-LASIK groups. PCE and PTE underwent slight backward displacement 6-month postoperatively and remain stable at the 5-year follow-up. Threshold of the ablation ratio for resisting forward displacement of posterior corneal surface was 27.3 and 27.1% for SMILE and FS-LASIK groups, respectively.