Change in Corneal Tomography Following Femtosecond Laser-Assisted Lenticule Intrastromal Keratoplasty (LIKE) in...

To report the refractive outcome of femtosecond laser-assisted lenticule intrastromal keratoplasty (LIKE) in correcting moderate to high hyperopia. Intraoperative effective optical zone (EOZ), centration offset, and postoperative higher order aberrations (HOAs) were analyzed to better understand factors affecting postoperative outcomes.

This was a prospective, consecutive case series study of LIKE for correcting hyperopia in one department from 2018 to 2023. Refraction, tomography, uncorrected and corrected distance visual acuity (UDVA/CDVA), EOZ, and decentration offset by an innovated method using semi-automated software (ImageJ; National Institutes of Health) were analyzed. Tomography measured the preoperative and postoperative refractive tomographic changes.

In the 18 eyes (9 participants) that underwent LIKE for correcting moderate to high hyperopia, the attempted spherical equivalent (SEQ) was +6.22 ± 0.85 diopters (D). One year postoperatively, 61% of all eyes had UDVA better than or equal to preoperative CDVA. In 78% of all eyes, the SEQ was less than 1.00 D from the attempted value. Compared to the programmed optical zone, the EOZ obtained after LIKE was significantly smaller (6.42 ± 0.15 vs 5.24 ± 0.23, P < .001). This was comparable to mild to moderate hyperopic LASIK treatment. The percentage of optical zone reduction was 18 ± 3%. The centration offset of the EOZ generated by LIKE was 0.27 ± 0.15 mm, and 94% of eyes had decentration within 0.5 mm. The induction of vertical coma and spherical aberration after LIKE were significantly higher.

LIKE is a promising procedure to maintain stable refraction and keratometry in correcting moderate to high hyperopia with sufficient EOZ, and acceptable decentration and corneal HOAs.