Corneal Lenticule Allotransplantation After Femtosecond Laser Small Incision Lenticule Extraction in Rabbits.

Abstract

To investigate the feasibility of allotransplanting extracted lenticules after femtosecond laser-assisted small incision lenticule extraction (SMILE) in rabbits and the subsequent healing process. Fourteen New Zealand white rabbits were divided evenly into 2 groups. The rabbits in group A received SMILE procedures with a -6.00 D correction. The lenticules from group A were immediately inserted into a femtosecond laser-created corneal stromal pocket in group B. After surgery, the anterior segment was assessed in vivo by slit-lamp microscopy, corneal topography, optical coherence tomography, and confocal microscopy. All eyes were enucleated for hematoxylin-eosin staining and transmission electron microscopy after the animals were killed. At postoperative day 1, there was moderate corneal edema in the implanted lenticule stroma. At 6 months, the lenticules were integrated with the surrounding tissue, and the boundary could not be identified through slit-lamp microscopy; regenerated branches of the corneal nerves were thicker than at postoperative month 1 as observed through confocal microscopy. The central corneal thickness increased by 58.75 ± 21.58 μm. The lenticules were gradually integrated with the surrounding tissue, and their density was similar to the adjacent tissue according to optical coherence tomography; however, a clear boundary between the lenticule and surrounding tissue was detectable using light microscopy and transmission electron microscopy, revealing disordered fibers and decreased keratocytes in implanted lenticules. In this model it is feasible and safe to allotransplant extracted corneal lenticules after SMILE. Healing of implanted lenticules after SMILE is stable at postoperative 6 months, but collagen fiber rearrangement requires further investigation.