title: Reversible Femtosecond Laser-Assisted Endokeratophakia Using Cryopreserved Allogeneic Corneal Lenticule.
abstract: OBJECTIVE
  To evaluate outcomes, reversibility, and wound healing response after the femtosecond laser-assisted endokeratophakia procedure in a rabbit model.
  
  
  METHODS
  Allogeneic rabbit corneal lenticules were cryopreserved in liquid nitrogen for 3 months. Twenty rabbits underwent the monocular endokeratophakia procedure and were divided into four groups according to the follow-up periods. The first three groups were killed at 3 days, 2 weeks, and 6 months after endokeratophakia, respectively. The rabbits in the fourth group received re-extraction of implanted lenticules at 6 months after endokeratophakia and were killed at 1 month after re-extraction. The rabbits were monitored by slit-lamp microscopy, ultrasonic pachymetry, in vivo confocal microscopy, optical coherence tomography (OCT), Corvis ST tonometry (Oculus Optikgeräte, Wetzlar, Germany), and Ocular Response Analyzer (Reichert Ophthalmic Instruments, Depew, NY). The tissue responses were analyzed by immunohistochemistry and transmission electron microscopy.
  
  
  RESULTS
  After endokeratophakia, corneal clarity improved continually with time. The changes in the refraction and corneal thickness were stable after implantation and could be reversed after re-extracting the lenticules. The interfaces were clearly visible on confocal microscopy and transmission electron microscopy images over the entire follow-up period. There were significant numbers of TUNEL-positive keratocytes in lenticules after endokeratophakia. CD11b-positive cells and deposition of fibronectin and tenascin were observed at earlier follow-up times. No alpha-smooth muscle actin-positive fibroblasts could be detected. In addition, the corneal biomechanics parameters were not significantly increased after endokeratophakia.
  
  
  CONCLUSIONS
  The endokeratophakia procedure using allogeneic cryopreserved lenticules was clinically stable and could be reversed. The wound healing response was mild, limited, and produced no scars. [J Refract Surg. 2016;32(8):569-576.].
authors: Yuan
authors: Y
authors: Sun
authors: Ting
authors: T
authors: Zhang
authors: Yuehua
authors: Y
authors: Zhou
authors: Manli
authors: M
authors: Liu
authors: Yugui
authors: Y
authors: Zhou
authors: Xiaonan
authors: X
authors: Yang
authors: Shengbei
authors: S
authors: Weng
authors: Chi-Ho
authors: CH
authors: To
authors: Quan
authors: Q
authors: Liu
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D003315:Cornea / Q000378:metabolism / Q000601:surgery* / Q000648:ultrastructure; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000637:transplantation*; D048988:Corneal Surgery, Laser / Q000379:methods*; D015925:Cryopreservation; D005136:Eye Proteins / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D020287:In Situ Nick-End Labeling; D054018:Lasers, Excimer / Q000627:therapeutic use; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D023421:Models, Animal; D011817:Rabbits; D066167:Slit Lamp; D014021:Tissue Preservation; D041623:Tomography, Optical Coherence; D014184:Transplantation, Homologous; D014945:Wound Healing / Q000502:physiology
chemical_list: D015415:Biomarkers; D005136:Eye Proteins