title: Safety evaluation of rabbit eyes on scleral collagen cross-linking by riboflavin and ultraviolet A.
abstract: BACKGROUND
  To evaluate the safety of the scleral collagen cross-linking (CXL) transferred from corneal CXL in rabbit eyes using histology and electroretinography (ERG).
  
  
  METHODS
  Stress-strain measurement was performed five rabbits 1 week after scleral CXL. Dark-adapted ERG was repeatedly applied on bilateral eyes of 10 rabbits before, and 1 week, 1 month and 3 months after the CXL operation. Histological analysis, terminal deoxynucleotidyl transferase dUTP nick-end labeling, the measurement of outer nuclear layer thickness and transmission electron microscopy were performed onto 15 rabbits at corresponding time points postoperatively.
  
  
  RESULTS
  The mechanical and biochemical stability of rabbit scleral tissues was statistically increased after the scleral CXL (P = .00). However, the dark-adapted ERG amplitudes were statistically reduced 1 week, 1 month and 3 months postoperatively (P < 0.05). Compared with the control eyes, apoptotic cells and ultrastructural changes can be found in the retinal layers of scleral cross-linked eyes.
  
  
  CONCLUSIONS
  According to the electrophysiological and histopathological results, the current scleral CXL laboratory technique is not safe enough for the postoperative visual function of rabbit eyes.
authors: Beijing Tongren Eye Center, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing Tongren Hospital of Capital Medical University, Beijing; Hebei Ophthalmology Key Lab, Hebeisheng Eye Hospital, Xingtai, Hebei Province, China.
authors: Mengmeng
authors: M
authors: Wang
authors: Fengju
authors: F
authors: Zhang
authors: Kegao
authors: K
authors: Liu
authors: Xu
authors: X
authors: Zhao
mesh_terms: D000818:Animals; D017209:Apoptosis; D001696:Biomechanical Phenomena; D003094:Collagen / Q000378:metabolism*; D003432:Cross-Linking Reagents; D003623:Dark Adaptation; D004548:Elasticity / Q000502:physiology*; D004596:Electroretinography; D020287:In Situ Nick-End Labeling; D046529:Microscopy, Electron, Transmission; D017319:Photosensitizing Agents / Q000009:adverse effects / Q000494:pharmacology*; D011817:Rabbits; D012160:Retina / Q000503:physiopathology / Q000648:ultrastructure; D012256:Riboflavin / Q000009:adverse effects / Q000494:pharmacology*; D012590:Sclera / Q000187:drug effects / Q000502:physiology*; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin
keywords: ERG; cross-linking; riboflavin; sclera; ultraviolet A (UVA)