title: Corneal crosslinking with genipin, comparison with UV-riboflavin in ex-vivo model.
abstract: OBJECTIVE
  To investigate the efficacy and safety of Genipin and UV-riboflavin crosslinking (UV-CLX) in corneal crosslinking.
  
  
  METHODS
  Porcine eyes were separated in groups for each crosslinker, genipin 0.25% UV-CLX (clinical crosslinking procedure), glutaraldehyde 0.1% (gold standard crosslinker), and control eyes. Intraocular pressure (IOP) was continuously monitored by a pressure sensor cannulated to the anterior chamber and the volume was changed. The changes in ocular pressure as a function of change of the ocular volume were evaluated. Ocular rigidity was calculated as the exponential of polynomial quadratic fit. Endothelial damage was evaluated in a viability assay with alizarin red staining as the changes in cell counts.
  
  
  RESULTS
  Significant changes in IOP were observed in the globes were the cornea was stiffened with genipin and UV-CLX treatment (volume 200 μl: Genipin 19.4 mmHg, UVCRX 18.8 mmHg, glutaraldehide 23.9 mmHg, versus control 14.7 mmHg, and 400 μl genipin 31.5 mmHg, UV-CLX 26.0 mmHg, glutaraldehide 37.3 mmHg versus control 18.7 mmHg). The mean ocular ridigity coefficient was genipin 0.0078 mmHg/μl, UV-CLX 0.0065 mmHg/μl, glutaraldehide 0.0092 mmHg/μl, and 0.0046 mmHg/μl for control eyes. Endothelial cell damage was 5.9±1.8% (control), 10.3±1.7% (UV-CLX), 9.4±1.5% (Genipin 0.25%), and 40.1±6.2% (glutaraldehide). Some granules were observed in the UV-CLX group. Reduction of keratocites was observed in the UV CRX crosslinking.
  
  
  CONCLUSIONS
  Corneal crosslinking was similar between UV-CLX and genipin with minimal toxicity to endothelial cells. Stiffened corneas by any method induced substancially higher IOP elevation when ocular volume is increased.
authors.affiliation: Department of Ophthalmology, Facultad de Medicina, Universidad Nacional de Colombia, Bogota DC, Colombia. myavilac@unal.edu.co
authors.forename: Marcel Y
authors.initials: MY
authors.lastname: Avila
authors.forename: Vanessa A
authors.initials: VA
authors.lastname: Gerena
authors.forename: Jose L
authors.initials: JL
authors.lastname: Navia
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D003315:Cornea / Q000166:cytology / Q000187:drug effects*; D060527:Corneal Keratocytes / Q000166:cytology / Q000187:drug effects*; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects*; D005976:Glutaral / Q000494:pharmacology; D007429:Intraocular Pressure / Q000187:drug effects / Q000502:physiology; D039823:Iridoids / Q000494:pharmacology*; D009924:Organ Culture Techniques; D012256:Riboflavin / Q000494:pharmacology; D013552:Swine; D014065:Tonometry, Ocular; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D039823:Iridoids; C007834:genipin; D005976:Glutaral; D012256:Riboflavin