title: Corneal Resistance to Keratolysis After Collagen Crosslinking With Rose Bengal and Green Light.
abstract: The purpose of this study was to evaluate the resistance to degradation by collagenase A of corneas that have been crosslinked with Rose Bengal and green light (RGX).
  
  
  
  The ex vivo crosslinking procedure was performed on enucleated rabbit corneas. Corneas were deepithelialized after applying 30% alcohol. Corneas were stained with Rose Bengal (RB, 0.1%) for 2 minutes and then exposed to green light (532 nm) at 0.25 W/cm2 for times to deliver doses of 50, 100, 150, or 200 J/cm2 (n = 5 per group). Five corneas were pretreated with riboflavin solution (0.1% riboflavin) for 15 minutes and irradiated with ultraviolet A (UVA) light (370 nm, 3 mW/cm2) for 30 minutes. Five corneas underwent only de-epithelialization and were otherwise untreated. Five corneas were stained with RB without light exposure. The central corneas of each group was removed with a 8.5-mm trephine and incubated at 37°C in 0.3% collagenase A solution. Time to dissolution of each cornea was compared across treatments.
  
  
  
  Corneas treated with RGX were treated with light fluences of 50, 100, 150, and 200 J/cm2; these corneas dissolved completely at 8.3 ± 1.2, 11.1 ± 1.4, 12.4 ± 1.7, and 15.7 ± 1.8 hours, respectively. Corneas treated by riboflavin and UVA light dissolved at 15.7 ± 1.7 hours, and nontreated corneas dissolved at 6.1 ± 1.3 hours. Corneas treated with only RB (no green light) dissolved at 9.3 ± 1.7 hours. Compared with the untreated corneas, all of the RB groups and the riboflavin-UVA-treated group of corneas degraded statistically significantly slower than untreated corneas (P < 0.05).
  
  
  
  Crosslinking with RGX increased corneal resistance to digestion by collagenase comparable to that produced by riboflavin and UVA treatment.
authors.affiliation: Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, United States 2Boston Eye Group, Brookline, Massachusetts, United States 3Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Ali
authors.initials: A
authors.lastname: Fadlallah
authors.affiliation: Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States 4Department of Ophthalmology, Shanghai First People's Hospital, Shanghai JiaoTong University, Shanghai, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Samer
authors.initials: S
authors.lastname: Arafat
authors.affiliation: Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Irene
authors.initials: I
authors.lastname: Kochevar
authors.affiliation: Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, United States 2Boston Eye Group, Brookline, Massachusetts, United States.
authors.forename: Samir
authors.initials: S
authors.lastname: Melki
authors.affiliation: Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Ciolino
mesh_terms: D000818:Animals; D003094:Collagen / Q000494:pharmacology*; D003315:Cornea / Q000187:drug effects* / Q000528:radiation effects*; D003316:Corneal Diseases / Q000175:diagnosis / Q000517:prevention & control*; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D004195:Disease Models, Animal; D005456:Fluorescent Dyes / Q000494:pharmacology; D008027:Light; D011817:Rabbits; D012395:Rose Bengal / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D005456:Fluorescent Dyes; D012395:Rose Bengal; D003094:Collagen