RT info:eu-repo/semantics/article T1 Corneal Collagen Ordering After In Vivo Rose Bengal and Riboflavin Cross-Linking A1 Germann, James A. A1 Martínez Enríquez, Eduardo A1 Martínez García, María del Carmen A1 Kochevar, Irene E. A1 Marcos, Susana K1 Colágeno corneal K1 Corneal collagen K1 2407 Biología Celular AB Purpose: Photoactivated cornea collagen cross-linking (CXL) increases corneal stiffness by initiating formation of covalent bonds between stromal proteins. Because CXL depends on diffusion to distribute the photoinitiator, a gradient of CXL efficiency with depth is expected that may affect the degree of stromal collagen organization. We used second harmonic generation (SHG) microscopy to investigate the differences in stromal collagen organization in rabbit eyes after corneal CXL in vivo as a function of depth and time after surgery.Methods: Rabbit corneas were treated in vivo with either riboflavin/UV radiation (UVX) or Rose Bengal/green light (RGX) and evaluated 1 and 2 months after CXL. Collagen fibers were imaged with a custom-built SHG scanning microscope through the central cornea (350 µm depth, 225 × 225 µm en face images). The order coefficient (OC), a metric for collagen organization, and total SHG signal were computed for each depth and compared between treatments.Results: OC values of CXL-treated corneas were larger than untreated corneas by 27% and 20% after 1 month and 38% and 33% after 2 months for the RGX and UVX, respectively. RGX OC values were larger than UVX OC values by 3% and 5% at 1 and 2 months. The SHG signal was higher in CXL corneas than untreated corneas, both at 1 and 2 months after surgery, by 18% and 26% and 1% and 10% for RGX and UVX, respectively.Conclusions: Increased OC corresponded with increased collagen fiber organization in CXL corneas. Changes in collagen organization parallel reported temporal changes in cornea stiffness after CXL and also, surprisingly, are detected deeper in the stroma than the regions stiffened by collagen cross-links. PB Association for Research in Vision and Ophthalmology SN 1552-5783 YR 2020 FD 2020 LK http://uvadoc.uva.es/handle/10324/45228 UL http://uvadoc.uva.es/handle/10324/45228 LA eng NO Investigative Ophthalmology & Visual Science March 2020, Vol.61, 28 NO Producción Científica DS UVaDOC RD 22-nov-2024