title: The Evaluation of Corneal Fragility After UVA/Riboflavin Crosslinking.
abstract: OBJECTIVE
  To evaluate the fragility of cornea after UVA/riboflavin crosslinking (CXL).
  
  
  METHODS
  Sixty New Zealand rabbits received UVA/riboflavin crosslinking treatment (wavelength 365 nm, irradiance 3.0 mW/cm, and total dose 5.4 J/cm) on right eyes. Animals were sacrificed before and immediately after treatment (day 0), day 1, 3, 7, and 28 after treatment. A 4×10 mm corneal strip for biomechanical evaluation was harvested after sacrifice. The corneal fragility was evaluated by measurement of elongation rate, whereby the elongation rate equals elongation length/baseline length.
  
  
  RESULTS
  The Youngs modulus and maximal stress were 1.41±0.51 MPa and 5.56±1.84 MPa before CXL, and increased to 2.31±0.68 MPa (P=0.008) and 9.25±2.74 MPa (P=0.04), respectively, on day 0, then maintained a stable level within a 28 days follow-up. The elongation rate was 62.04±9.34% before CXL and decreased to 48.95%±8.24% (P=0.02) on day 0, then maintained a stable level within a 28 days follow-up.
  
  
  CONCLUSIONS
  This study showed an increase in the corneal fragility after UVA/riboflavin crosslinking along with an increase in the corneal stiffness. A long-term follow-up should be taken to evaluate the potential deleterious effect of the increasing corneal fragility after UVA/riboflavin crosslinking.
authors.affiliation: Department of Ophthalmology (Z.L., Y.W., Y.X., C.Z., G.M.), Shandong Provincial Hospital affiliated to Shandong University, Jinan, China; and Department of Ophthalmology and Visual Sciences (V.J.), The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Li
authors.forename: Yumeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Yanyun
authors.initials: Y
authors.lastname: Xu
authors.forename: Vishal
authors.initials: V
authors.lastname: Jhanji
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Zhang
authors.forename: Guoying
authors.initials: G
authors.lastname: Mu
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D003094:Collagen / Q000378:metabolism; D003315:Cornea / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*; D003432:Cross-Linking Reagents / Q000009:adverse effects*; D004195:Disease Models, Animal; D017319:Photosensitizing Agents / Q000009:adverse effects*; D011817:Rabbits; D012256:Riboflavin / Q000009:adverse effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin