Achieved Lenticule Diameter and Functional Optical Zone in Hyperopic Eyes After Lenticule Intrastromal Keratoplasty

Abstract

To investigate achieved lenticule diameter (ALD) and functional optical zone (FOZ) following femtosecond laser-assisted lenticule intrastromal keratoplasty (FS-LIKE) or small incision lenticule intrastromal keratoplasty (SMI-LIKE). Small incision lenticule extraction (SMILE)-derived human lenticules were placed on the surface of a contact glass (CG) and model eye (ME). Ex vivo ALDs were assessed at different hydration times. The ALD and FOZ were obtained using optical coherence tomography and Scheimpflug tomography at 6 months after lenticule implantation. At 1 hour after hydration, lenticules achieved a slightly larger CG-loading ALD (6.63 ± 0.07 mm) and similar ME-loading ALD (6.53 ± 0.07 mm) as compared to a programmed optical zone (POZ) of 6.5 mm (P < .001). At 6 months after surgery, FS-LIKE with a POZ of 6.5 mm obtained an ALD of 6.20 ± 0.21 mm, which was larger than SMI-LIKE with a POZ of 6.64 mm (5.90 ± 0.14 mm, P = .001). The mean FOZ diameters were 5.33 ± 0.28 and 5.11 ± 0.14 mm for the FS-LIKE and SMI-LIKE groups, respectively (P = .022). The absence of significant differences in the ALD and FOZ among the different meridians indicated that the achieved lenticule and optical zone shapes were circular. An accurate lenticular size could be obtained from SMILE, and FS-LIKE could achieve a larger FOZ than SMI-LIKE, attributed to attaining a larger ALD. [J Refract Surg. 2022;38(12):791-796.].