Effective Optical Zone Diameter, Decentration and High-Order Aberrations Following LIKE in Correcting Moderate to High Hyperopia

Abstract

Background To compare the changes in effective optical zone (EOZ), centration offset and higher-order aberrations between femtosecond laser–assisted lenticule intrastromal keratoplasty (LIKE) and femtosecond-assisted laser in-situ keratomileusis (LASIK) for correcting hyperopia. Methods This is a retrospective unpaired nested case-control study reviewing data of series cases for hyperopia treatment in our department from 2018 to 2023. It mainly includes two surgeries and sets up two groups: LIKE and Hyperopic-LASIK group. Data primarily includes corrected minimum hyperopia ≥ + 1.00D and examination results within three months of follow-up at least. Results Cases included in LIKE group were mainly corrected for moderate-to-high- hyperopia (SEQ = + 6.14D), and in HLASIK group were corrected for low-to-moderate- hyperopia (SEQ = + 3.54D). The programmed optical zone diameter in LIKE was significantly smaller than postoperative result in HLASIK (6.27mm VS. 6.56mm). Through a novel measuring method of EOZ based on the ImageJ software, EOZ diameter obtained after LIKE procedure was significantly larger than that obtained after HLASIK (5.22mm VS. 4.61mm). The centration offset of the EOZ generated by LIKE was similar to that in HLASIK (0.27mm VS. 0.24mm). In LIKE, 95% of eyes had decentration within 0.5mm. The negative induction of corneal asphericity and spherical aberration after LIKE was significant, but even if it was correcting the higher hyperopia, that still has no significant difference with HLASIK. Conclusion Compared with HLASIK, LIKE has the potential to get larger EOZ and relative natural corneal morphology in correcting moderate to high hyperopia. And we propose a novel method for analyzing EOZ, which will help to improve the efficiency, accuracy, and convenience of graphical analysis.