Miao He1, He Jin1, Hong He2, Hui Ding2, Wei Wang1, Liangping Liu1, Chi Zhang3, Xingwu Zhong1,2. 1. Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, China. 2. Hainan Eye Hospital, Zhongshan Ophthalmic Center, Sun Yat-sen University, Haikou, Hainan Province, China. 3. Department of Ophthalmology, The First People's Hospital of Foshan, Foshan, Guang Dong Province, China.
Abstract
PURPOSE: To evaluate the feasibility and safety of xenogeneic endokeratophakia in rhesus monkeys and to explore the effects of a concave lenticule on refractive power. METHODS: Three adult New Zealand white rabbits and 6 healthy rhesus monkeys were used. The xenogenic concave grafts were created from the rabbits using a modified small incision lenticule extraction technique; after being cryopreserved in glycerol for 1 week, the grafts were implanted into the monkey recipient corneas. Spherical equivalent (SE), central corneal thickness, and keratometry curvature were assessed preoperatively, 1 week, 1, 4 and 6 months postoperatively. The quality of the xenogenic graft was also assessed by slit-lamp microscopy, in vivo confocal microscopy, and optical coherence tomography with anterior segment imaging. RESULTS: The graft appeared to be swollen a day after the operation but reduced considerably after a week. A trend of a lower refractive power (hyperopic shift) was demonstrated in relation to the SE after concave graft implantation. The mean SE increased from -0.60 ± 1.31 (median -0.69, interquartile range -1.00 to 0.50) preoperatively to 0.75 ± 1.27 (median 1.38, interquartile range -0.25 to 1.63) at 1 month postoperatively (P = 0.01). Central corneal thickness was significantly thicker each time after surgery compared with that recorded preoperatively (P < 0.01). The anterior and posterior interface between the graft and stroma was visible during the study. Corneal nerve regeneration was evident at 6 months postoperatively. The xenogeneic concave graft was stable and transparent at follow-up. Severe adverse events or evidence of a rejection response were not observed. CONCLUSIONS: Femtosecond laser-assisted small incision endokeratophakia using a xenogeneic corneal lenticule seems to be feasible and safe, which may provide a new method for myopia correction and keratoconus treatment.
PURPOSE: To evaluate the feasibility and safety of xenogeneic endokeratophakia in rhesus monkeys and to explore the effects of a concave lenticule on refractive power. METHODS: Three adult New Zealand white rabbits and 6 healthy rhesus monkeys were used. The xenogenic concave grafts were created from the rabbits using a modified small incision lenticule extraction technique; after being cryopreserved in glycerol for 1 week, the grafts were implanted into the monkey recipient corneas. Spherical equivalent (SE), central corneal thickness, and keratometry curvature were assessed preoperatively, 1 week, 1, 4 and 6 months postoperatively. The quality of the xenogenic graft was also assessed by slit-lamp microscopy, in vivo confocal microscopy, and optical coherence tomography with anterior segment imaging. RESULTS: The graft appeared to be swollen a day after the operation but reduced considerably after a week. A trend of a lower refractive power (hyperopic shift) was demonstrated in relation to the SE after concave graft implantation. The mean SE increased from -0.60 ± 1.31 (median -0.69, interquartile range -1.00 to 0.50) preoperatively to 0.75 ± 1.27 (median 1.38, interquartile range -0.25 to 1.63) at 1 month postoperatively (P = 0.01). Central corneal thickness was significantly thicker each time after surgery compared with that recorded preoperatively (P < 0.01). The anterior and posterior interface between the graft and stroma was visible during the study. Corneal nerve regeneration was evident at 6 months postoperatively. The xenogeneic concave graft was stable and transparent at follow-up. Severe adverse events or evidence of a rejection response were not observed. CONCLUSIONS: Femtosecond laser-assisted small incision endokeratophakia using a xenogeneic corneal lenticule seems to be feasible and safe, which may provide a new method for myopia correction and keratoconus treatment.
Authors: Martina Nemcokova; Jakub Dite; Yun Min Klimesova; Magdalena Netukova; Pavel Studeny Journal: Cell Tissue Bank Date: 2022-02-06 Impact factor: 1.522