title: Transplantation of tissue-engineered epithelial cell sheets after excimer laser photoablation reduces postoperative corneal haze.
abstract: OBJECTIVE
  To apply tissue-engineered cell sheet transplantation after excimer laser keratectomy as a novel approach for the reduction of postoperative corneal haze.
  
  
  METHODS
  Limbal biopsy specimens were obtained, and epithelial cells were cultured on temperature-responsive culture inserts without the use of feeder cells. Laser keratectomy (7.0-mm ablation zone and 160-microm depth) was performed in the contralateral eye, and autologous epithelial cell sheets were transplanted to the ablated corneal stroma. Transplant and control group eyes were assessed by slit lamp biomicroscopy, and corneal haze was scored in a masked fashion, according to the Fantes grading scale. For further examination histologic and immunohistochemical analyses were performed.
  
  
  RESULTS
  Tissue-engineered cell sheets produced stable attachment to the laser-ablated sites, resulting in epithelialization, 5 minutes after transplantation. Conversely, control corneas required 3 to 5 days for complete re-epithelialization. At both 1 and 2 months after surgery, corneal haze was significantly inhibited in the transplant group. Histologic analyses showed that the number of keratocytes undergoing apoptosis was decreased in the transplant group at 3 days after surgery. Similarly, the expression of both collagen III and alpha-smooth muscle actin, which may enhance corneal haze, were diminished in the transplant group at 2 months.
  
  
  CONCLUSIONS
  The transplantation of tissue-engineered epithelial cell sheets can successfully prevent the development of corneal haze after excimer laser keratectomy.
authors.affiliation: Department of Ophthalmology, Osaka University Medical School, Osaka, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Hayashida
authors.forename: Kohji
authors.initials: K
authors.lastname: Nishida
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamato
authors.forename: Joseph
authors.initials: J
authors.lastname: Yang
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sugiyama
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Watanabe
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hori
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Maeda
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Tano
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D017690:Cell Transplantation; D018920:Coculture Techniques; D024061:Collagen Type III / Q000378:metabolism; D003315:Cornea / Q000601:surgery*; D003318:Corneal Opacity / Q000517:prevention & control*; D004847:Epithelial Cells / Q000378:metabolism / Q000637:transplantation*; D019573:Epithelium, Corneal / Q000378:metabolism / Q000637:transplantation; D005347:Fibroblasts / Q000473:pathology; D054018:Lasers, Excimer; D018903:Photorefractive Keratectomy; D011183:Postoperative Complications / Q000517:prevention & control*; D011817:Rabbits; D023822:Tissue Engineering
chemical_list: D000199:Actins; D024061:Collagen Type III