title: A new method of detecting changes in corneal health in response to toxic insults.
abstract: The size and arrangement of stromal collagen fibrils (CFs) influence the optical properties of the cornea and hence its function. The spatial arrangement of the collagen is still questionable in relation to the diameter of collagen fibril. In the present study, we introduce a new parameter, edge-fibrillar distance (EFD) to measure how two collagen fibrils are spaced with respect to their closest edges and their spatial distribution through normalized standard deviation of EFD (NSDEFD) accessed through the application of two commercially available multipurpose solutions (MPS): ReNu and Hippia. The corneal buttons were soaked separately in ReNu and Hippia MPS for five hours, fixed overnight in 2.5% glutaraldehyde containing cuprolinic blue and processed for transmission electron microscopy. The electron micrographs were processed using ImageJ user-coded plugin. Statistical analysis was performed to compare the image processed equivalent diameter (ED), inter-fibrillar distance (IFD), and EFD of the CFs of treated versus normal corneas. The ReNu-soaked cornea resulted in partly degenerated epithelium with loose hemidesmosomes and Bowman's collagen. In contrast, the epithelium of the cornea soaked in Hippia was degenerated or lost but showed closely packed Bowman's collagen. Soaking the corneas in both MPS caused a statistically significant decrease in the anterior collagen fibril, ED and a significant change in IFD, and EFD than those of the untreated corneas (p<0.05, for all comparisons). The introduction of EFD measurement in the study directly provided a sense of gap between periphery of the collagen bundles, their spatial distribution; and in combination with ED, they showed how the corneal collagen bundles are spaced in relation to their diameters. The spatial distribution parameter NSDEFD indicated that ReNu treated cornea fibrils were uniformly distributed spatially, followed by normal and Hippia. The EFD measurement with relatively lower standard deviation and NSDEFD, a characteristic of uniform CFs distribution, can be an additional parameter used in evaluating collagen organization and accessing the effects of various treatments on corneal health and transparency.
authors: Medical Genetics Unit, Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Via Fossato di Mortara 74, I-44121 Ferrara, Italy. Electronic address: mohammadfaisal.khan@unife.it.
authors: Mohammad Faisal Jamal
authors: MFJ
authors: Khan
authors: Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India.
authors: Tapas C
authors: TC
authors: Nag
authors: Department of Agricultural and Biosystems Engineering, North Dakota State University, 1221 Albrecht Boulevard, Fargo, ND 58102, USA.
authors: C
authors: C
authors: Igathinathane
authors: Faculty of Health, Visual and Ophthalmic Optics Group (Chronic Disease and Ageing Domain), Institute of Health and Biomedical Innovation, School of Optometry and Vision Sciences, Q Block, Kelvin Grove, Brisbane, Queensland 4059, Australia.
authors: Uchechukwu L
authors: UL
authors: Osuagwu
authors: Medical Genetics Unit, Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Via Fossato di Mortara 74, I-44121 Ferrara, Italy.
authors: Michele
authors: M
authors: Rubini
mesh_terms: D000818:Animals; D002417:Cattle; D018639:Contact Lens Solutions / Q000008:administration & dosage / Q000633:toxicity*; D003315:Cornea / Q000737:chemistry* / Q000187:drug effects / Q000648:ultrastructure*; D005109:Extracellular Matrix / Q000648:ultrastructure; D024022:Fibrillar Collagens / Q000032:analysis; D046529:Microscopy, Electron, Transmission / Q000379:methods*
chemical_list: D018639:Contact Lens Solutions; D024022:Fibrillar Collagens
keywords: Bovine cornea; Collagen fibrils; Contact lens; Edge fibrillar distance; Electron microscopy; ImageJ; Multipurpose solutions