Femtosecond Laser-Assisted Keyhole Endokeratophakia: Correction of Hyperopia by Implantation of an Allogeneic Lenticule Obtained by SMILE From a Myopic Donor

PURPOSE: To describe endokeratophakia in which a small incision lenticule extraction (SMILE) lenticule from a myopic patient is implanted into a recipient eye through a small incision to correct hyperopia. METHODS: A 23-year-old aphakic woman presented following cataract surgery to remove a childhood congenital cataract with hyperopia of + 12.00 1.50 x 155, corrected distance visual acuity of counting fingers, and exotropia. A SMILE procedure using the VisuMax femto-second laser (Carl Zeiss Meditec, Jena, Germany) was performed on a donor patient with high myopia and the extracted lenticule was stored (power -10.50 diopter sphere, optical zone 5.75 mm, central lenticule thickness 127 mu m). In the recipient eye, a pocket lamellar incision was created using the VisuMax SMILE software. The upper interface was separated and the donor lenticule was inserted through the small incision. RESULTS: One year postoperatively, retinoscopy refraction was +7.50 -3.00 x 150, a spherical equivalent refraction reduction of 5.25 diopters. Mean keratometric power increased by 2.91 diopters. The posterior surface elevation changed significantly with a central bulge into the anterior chamber. Central corneal thickness by Pentacam (Oculus Optikgerate, Wetzlar, Germany) increased by 121 mu m. Central lenticule thickness was 130 mu m and central epithelial thickness was 43 mu m measured by RTVue OCT (Optovue Inc., Fremont, CA). The cornea remained clear over the 1-year postoperative period. CONCLUSIONS: Endokeratophakia appears to be a viable procedure for correcting hyperopia on the cornea by implantation of an extracted myopic SMILE lenticule from a donor patient. However, posterior surface changes and epithelial remodeling resulted in only 50% of the intended correction. No adverse side effects were observed following implantation of donor tissue for 1 year.