title: Effects of collagen cross-linking on the interlamellar cohesive strength of porcine cornea.
abstract: OBJECTIVE
  To determine the interlamellar cohesive strength (ICS) of porcine cornea before and after collagen cross-linking using riboflavin and ultraviolet A (UVA) irradiation.
  
  
  METHODS
  Corneal flaps, 130 μm thick, were created with a microkeratome. Cross-linking was accomplished with 0.1% riboflavin and UVA irradiation for 30 minutes (3 mW/cm, 5.4 J/cm) at a distance of 10 mm. Two experiments were performed. (1) The maximal ICS between corneal flap and the stroma was determined and histological examination was performed. (2) The mean stromal ICS was measured. Untreated eyes served as controls in all experiments.
  
  
  RESULTS
  The mean maximum flap-stroma ICS was 0.088 ± 0.046 N/mm in the experimental group and 0.012 ± 0.004 N/mm in the control group (P = 0.009). In experiment 2, incomplete (2 mm long) corneal flaps were used and the mean stromal ICS was 0.750 ± 0.077 N/mm in the experimental group and 0.338 ± 0.046 N/mm in the control group (P < 0.0001). Histological examination showed an irregular ragged separation of the surface in the stromal margin of the cornea with cross-linking, but a smooth separation surface in the cornea without cross-linking.
  
  
  CONCLUSIONS
  Collagen cross-linking activated by riboflavin/UVA increases ICS in porcine corneas.
authors.affiliation: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Tao
authors.forename: Yong
authors.initials: Y
authors.lastname: Sun
authors.forename: Chuanqing
authors.initials: C
authors.lastname: Zhou
authors.forename: Zhaolong
authors.initials: Z
authors.lastname: Han
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Ren
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism*; D003315:Cornea / Q000187:drug effects / Q000502:physiology*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D023421:Models, Animal; D017319:Photosensitizing Agents / Q000627:therapeutic use; D012256:Riboflavin / Q000627:therapeutic use; D013524:Surgical Flaps; D013552:Swine; D013718:Tensile Strength / Q000502:physiology*; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin