Ithar M Beshtawi1, Riaz Akhtar2, M Chantal Hillarby3, Clare O'Donnell4, Xuegen Zhao5, Arun Brahma6, Fiona Carley6, Brian Derby5, Hema Radhakrishnan7. 1. a Optometry Department, Faculty of Medicine and Health Sciences , An-Najah National University , Nablus , State of Palestine . 2. b Centre for Materials and Structures, School of Engineering, University of Liverpool , Liverpool , UK . 3. c Stopford Building, Centre For Tissue Injury and Repair, Institute of Inflammation and Repair, University of Manchester , Manchester , UK . 4. d Optegra Eye Sciences, Optegra Manchester Eye Hospital , Manchester , UK . 5. e Manchester Materials Science Centre, School of Materials, The University of Manchester , Manchester , UK . 6. f Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre , Manchester , UK and. 7. g Faculty of Life Sciences , The University of Manchester , Manchester , UK.
Abstract
PURPOSE: To assess the biomechanical changes of collagen cross-linking on keratoconic corneas in vitro. METHODS: Six keratoconic corneal buttons were included in this study. Each cornea was divided into two halves, where one half was cross-linked and the other half was treated with riboflavin only and served as control. The biomechanical changes of the corneal tissue were measured across the stroma using scanning acoustic microscopy (SAM). RESULTS: In the cross-linked corneas, there was a steady decrease in the magnitude of speed of sound from the anterior region through to the posterior regions of the stroma. The speed of sound was found to decrease slightly across the corneal thickness in the control corneas. The increase in speed of sound between the cross-linked and control corneas in the anterior region was by a factor of 1.039×. CONCLUSION: A higher speed of sound was detected in cross-linked keratoconic corneal tissue when compared with their controls, using SAM. This in vitro model can be used to compare to the cross-linking results obtained in vivo, as well as comparing the results obtained with different protocols.
PURPOSE: To assess the biomechanical changes of collagen cross-linking on keratoconic corneas in vitro. METHODS: Six keratoconic corneal buttons were included in this study. Each cornea was divided into two halves, where one half was cross-linked and the other half was treated with riboflavin only and served as control. The biomechanical changes of the corneal tissue were measured across the stroma using scanning acoustic microscopy (SAM). RESULTS: In the cross-linked corneas, there was a steady decrease in the magnitude of speed of sound from the anterior region through to the posterior regions of the stroma. The speed of sound was found to decrease slightly across the corneal thickness in the control corneas. The increase in speed of sound between the cross-linked and control corneas in the anterior region was by a factor of 1.039×. CONCLUSION: A higher speed of sound was detected in cross-linked keratoconic corneal tissue when compared with their controls, using SAM. This in vitro model can be used to compare to the cross-linking results obtained in vivo, as well as comparing the results obtained with different protocols.