title: Confocal microscopy evaluation of stromal fluorescence intensity after standard and accelerated iontophoresis-assisted corneal cross-linking.
abstract: The aim of this study is to determine modifications in stromal fluorescence intensity after different corneal cross-linking (CXL) procedures and to correlate stromal fluorescence to corneal biomechanical resistance. For confocal microscopy study, 15 human cadaver corneas were examined. Three served as control (group 1), three were just soaked with iontophoresis procedure (group 2), three were treated with standard epi-off technique (group 3), and six underwent iontophoresis imbibition. Three of later six were irradiated for 30 min with 3 mW/cm2UVA (group 4) and three for 9 min at 10 mW/cm2UVA (group 5). Confocal microscopy was performed to quantify the fluorescence intensity in the cornea at different stromal depths. For biomechanical study, 30 human cadaver corneas were randomly divided into five groups and treated as previously described. Static stress-strain measurements of the corneas were performed. Iontophoresis imbibition followed by 10mW/cm2irradiation proved to increase stromal fluorescence into the corneal stroma and significant differences were revealed between group 3 and 5 both at 100 (p = 0.0171) and 250 µm (p = 0.0024), respectively. Biomechanical analysis showed an improvement of corneal resistance in group 5. Iontophoresis imbibition followed by accelerated irradiation increased the stromal fluorescence and is related to an improvement of biomechanical resistance. This approach may represent a new strategy to achieve greater concentrations of riboflavin without removing corneal epithelium and improve clinical results while reducing the side effects of CXL.
authors.affiliation: Department of Medicine and Ageing Sciences, Ophthalmology Clinic, University "G. d' Annunzio" of Chieti-Pescara, 66100, Chieti-Pescara, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Lanzini
authors.affiliation: Department of Medicine and Ageing Sciences, Visual Science Laboratory, CeSI, University "G. d' Annunzio" of Chieti-Pescara, Chieti-Pescara, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Curcio
authors.affiliation: Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Spoerl
authors.affiliation: Department of Medicine and Ageing Sciences, Ophthalmology Clinic, University "G. d' Annunzio" of Chieti-Pescara, 66100, Chieti-Pescara, Italy. roberta.calienno@gmail.com.
authors.forename: Roberta
authors.initials: R
authors.lastname: Calienno
authors.affiliation: Ophthalmology Clinic, Campus Bio-medico University of Rome, Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Mastropasqua
authors.affiliation: Department of Medicine and Ageing Sciences, Ophthalmology Clinic, University "G. d' Annunzio" of Chieti-Pescara, 66100, Chieti-Pescara, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Colasante
authors.affiliation: Ophthalmology Clinic, University of Verona, Verona, Italy.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Mastropasqua
authors.affiliation: Department of Medicine and Ageing Sciences, Ophthalmology Clinic, University "G. d' Annunzio" of Chieti-Pescara, 66100, Chieti-Pescara, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Nubile
authors.affiliation: Department of Medicine and Ageing Sciences, Ophthalmology Clinic, University "G. d' Annunzio" of Chieti-Pescara, 66100, Chieti-Pescara, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Mastropasqua
mesh_terms: D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D002102:Cadaver; D003094:Collagen / Q000378:metabolism*; D003315:Cornea / Q000187:drug effects / Q000473:pathology* / Q000503:physiopathology / Q000528:radiation effects; D003319:Corneal Stroma / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D005453:Fluorescence; D006801:Humans; D007478:Iontophoresis / Q000379:methods*; D018613:Microscopy, Confocal; D017319:Photosensitizing Agents / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen
keywords: Cross-linking; Iontophoresis; Riboflavin