title: Comparison of riboflavin/ultraviolet-A cross-linking in porcine, rabbit, and human sclera.
abstract: OBJECTIVE
  To compare the biomechanical properties of porcine, rabbit, and human sclera before and after riboflavin/ultraviolet-A (UVA) collagen cross-linking (CXL).
  
  
  METHODS
  Eight rabbits, 8 porcine eyeballs, and 8 human eyeballs were included. One rabbit eye and half of each bisected human and porcine eyeball were treated with riboflavin/UVA CXL. Untreated fellow rabbit eyes and eyeball halves served as controls. A 10 mm × 20 mm scleral band was harvested from each specimen. From this band, two 3.5 mm × 15.0 mm strips were prepared for biomechanical testing. The biomechanical parameters were ultimate stress, stress and Young's modulus.
  
  
  RESULTS
  Values of stress, and Young's modulus showed that human sclera was 4 times stiffer than porcine sclera and 3 times stiffer than rabbit sclera. In rabbit sclera, both the stress and Young's modulus were significantly increased by CXL (P < 0.05). In porcine sclera, only the ultimate stress was significantly increased by CXL (P < 0.05). The biomechanical properties of human sclera were not statistically affected by CXL (P > 0.05).
  
  
  CONCLUSIONS
  Human sclera has higher biomechanical stiffness than porcine and rabbit sclera. With the same irradiation dose, riboflavin/UVA CXL increases the biomechanical stiffness of rabbit sclera but not porcine or human sclera.
authors: Department of Ophthalmology, The Second People's Hospital of Jinan, 148 Jingyi Road, Jinan, Shandong 250001, China.
authors: Yali
authors: Y
authors: Zhang
authors: Department of Ophthalmology, Shandong Provincial Hospital Affiliated to Shandong University, No. 324 Jingwuweiqi Road, Jinan, Shandong 250021, China.
authors: Zhiwei
authors: Z
authors: Li
authors: Department of Ophthalmology, The Second People's Hospital of Jinan, 148 Jingyi Road, Jinan, Shandong 250001, China.
authors: Lei
authors: L
authors: Liu
authors: Department of Ophthalmology, The Second People's Hospital of Jinan, 148 Jingyi Road, Jinan, Shandong 250001, China.
authors: Xuguang
authors: X
authors: Han
authors: School of Nursing, Binzhou Medical University, No. 346 Guanhai Road, Laishan District, Yantai, Shandong 264003, China.
authors: Xiaomin
authors: X
authors: Zhao
authors: Department of Ophthalmology, Shandong Provincial Hospital Affiliated to Shandong University, No. 324 Jingwuweiqi Road, Jinan, Shandong 250021, China.
authors: Guoying
authors: G
authors: Mu
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003094:Collagen / Q000737:chemistry*; D006801:Humans; D017319:Photosensitizing Agents / Q000008:administration & dosage; D011817:Rabbits; D012256:Riboflavin / Q000737:chemistry* / Q000378:metabolism; D012590:Sclera; D013552:Swine; D014466:Ultraviolet Rays
chemical_list: D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin