Long-Term Study Of Biomechanics And Associated Factors Of Lenticule Intrastromal Keratoplasty (Like) For The Correction Of Hyperopia

To investigate on long-term corneal biomechanical changes and influencing factors of lenticule intrastromal keratoplasty (LIKE) in the treatment of hyperopia.

The study is in compliance with tenets of the Declaration of Helsinki and in approval of the Ethics Committee of the Eye & ENT Hospital of Fudan University. Written informed consent was obtained from each patient.

9 eyes of 9 patients who underwent LIKE in the Eye and ENT Hospital of Fudan University (Shanghai, China) from May 2015 to September 2022 were recruited. 2 patients received allogenic lenticule graft and 7 received autologous lenticule extracted from the contralateral eye during SMILE.

9 eyes of 9 patients with mean age of 34.00±9.34 years old were enrolled. Full-scale examinations were conducted on all patients preoperatively and during 2 years of follow-ups. Topographic and biomechanical parameters were evaluated with Pentacam and Corvis ST preoperatively and in all follow-up visits.

All surgeries were uneventful without complications. Safety index was 1.27±0.64 and efficacy index was 0.96±0.62 at the last follow-up. Central corneal thickness (CCT) and thinnest corneal thickness (TCT) significantly increased 2 years postoperatively, while Ambrosio relational thickness horizontal (ARTh) and Corvis biomechanical index (CBI) decreased. Deformation amplitude ratio (DA ratio), stiffness parameter at the first applanation (SP-A1) and posterior elevation (PE) remained stable 2 years after LIKE. DA ratio was negatively correlated with CCT and TCT, while SP-A1 was positively correlated with CCT and TCT. ARTh was positively correlated with TCT (r=0.47, P=0.049*), and CBI was positively correlated with PE (r=0.63, P=0.005*).

Lenticule intrastromal keratoplasty (LIKE) for correction of hyperopia is safe and effective in the long term. PE remained stable and CBI improved 2 years postoperatively.