Cornea - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group - CorneaConclusions: Scanning acoustic microscopy is a novel tool forexamining the biomechanical properties of human corneal tissue. Itwas used successfully to assess corneal stiffness after applyingcollagen cross-linking. Similar results were observed in corneastreated with low and high intensity cross-linking protocols.Table 1. Patient satisfaction and quality of vision questionnaireresults.Commercial Relationships: Rose K. Sia, None; Richard D.Stutzman, None; Joseph F. Pasternak, None; Denise S. Ryan,None; Jennifer B. Eaddy, None; Lorie A. Logan, None; LamarrPeppers, None; Edward W. Trudo, None; Kraig S. Bower, NoneSupport: Dept of Defense W81XWH-09-2-0018Clinical Trial: NCT01097525Program Number: 3115 Poster Board Number: D0050Presentation Time: 8:30 AM - 10:15 AMBiomechanical changes in Human Corneas after Low and HighIntensity Collagen Cross-Linking Treatment measured usingScanning Acoustic MicroscopyIthar M. Beshtawi 1 , Riaz Akhtar 2 , Chantal Hillarby 3 , ClareO'Donnell 1, 4 , Xuegen Zhao 5 , Arun Brahma 6 , Fiona M. Carley 6 , BrianDerby 5 , Hema Radhakrishnan 1 . 1 Faculty of Life Sciences, TheUniversity of Manchester, Manchester, United Kingdom; 2 School ofEngineering, University of Liverpool, Liverpool, United Kingdom;3 School of Clinical and Laboratory Science, The University ofManchester, Manchester, United Kingdom; 4 Optegra, Manchester,United Kingdom; 5 School of Materials, The University ofManchester, Manchester, United Kingdom; 6 Manchester Royal EyeHospital, Manchester, United Kingdom.Purpose: To assess and compare the biomechanical properties ofpostmortem human corneas after low and high intensity collagencross-linking using scanning acoustic microscopy (SAM).Methods: Two groups of five human corneal pairs were included inthe study. In group (A), five corneas were treated with low intensitycross-linking (epithelium removed, 0.1% riboflavin applied for 30minutes following which UV-A irradiation (365 nm, 3mW/cm 2 ) wasapplied for 30 minutes alongside the riboflavin solution) Thecontralateral cornea was exposed to riboflavin only, and served as acontrol. In group (B), five corneas were treated with high-intensitycollagen cross-linking (epithelium removed, riboflavin 0.1% solutionapplication for 30 minutes prior to UV-A irradiation (365 nm,9mW/cm 2 ) for 10 minutes, while the riboflavin was re-applied. Thecontralateral cornea was exposed to riboflavin only, and served as acontrol. The biomechanical properties of all corneas were testedusing SAM.Results: In the low intensity cross-linked corneas (group A), thespeed of sound of the treated corneas was 1674.51 ± 21.38 ms -1anteriorly and 1598.24 ± 27.83 ms -1 posteriorly, while it was 1593.96± 22.51 ms -1 anteriorly and posteriorly 1578.64 ± 18.83 ms -1 in theuntreated corneas. In the high-intensity cross-linked corneas (groupB), the speed of sound of the treated corneas was 1663.55 ± 20.16ms -1 anteriorly and 1593.17 ± 20.30 ms -1 posteriorly, while it was1582.38 ± 15.30 ms -1 anteriorly and 1564.12 ± 18.46 ms -1 posteriorlyin the untreated corneas. The speed of sound is directly proportionalto the stiffness of the tissue. Therefore the results indicate thatcorneal stiffness changes are similar in the low and high intensitycross-linking groups.The anterior and posterior (200 x 200) µm portion of low intensitycross-linked (A and B, respectively) and untreated (C and Drespectively) corneal sections.The anterior and posterior (200 x 200) µm portion of high intensitycross-linked (A and B, respectively) and untreated (C and Drespectively) corneal sections.Commercial Relationships: Ithar M. Beshtawi, None; RiazAkhtar, None; Chantal Hillarby, None; Clare O'Donnell, None;Xuegen Zhao, None; Arun Brahma, None; Fiona M. Carley,None; Brian Derby, None; Hema Radhakrishnan, NoneProgram Number: 3116 Poster Board Number: D0051Presentation Time: 8:30 AM - 10:15 AMInflammatory and lacrimal gland proteins in the tear film afterfemtosecond LASIKAndrea Petznick 1 , Lei Zhou 1, 3 , Roger W. Beuerman 1, 3 , Siew KwanKoh 1 , Louis Tong 2, 1 , Jodhbir S. Mehta 2, 1 . 1 Ocular Surface ResearchGroup, Singapore Eye Research Institute, Singapore, Singapore;2 Singapore National Eye Centre, Singapore, Singapore; 3 Duke-NUSGraduate Medical School, Singapore, Singapore.Purpose: Dry eye is a major side effect of LASIK. It has not beenclear if these complaints are caused by inflammatory changes orregenerative corneal nerve changes. A proteomics study of tears wascarried out with patients who underwent femtosecond LASIK toaddress two questions: 1) Is LASIK-associated dry eye a result ofinflammation? 2) Does the newer femtosecond platform VisuMaxusing smaller flap, higher repetition rate, lower laser pulse energy anddifferent corneal suction reduce adverse ocular surface changes?Methods: In a prospective contra-lateral paired eye study, cornealflaps of 22 patients were created by either the VisuMax or IntraLaselaser. Tear samples were collected before surgery, and at 1 week and3 months postoperatively using Schirmer’s strips. A panel of dry eye©2013, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permissionto reproduce any abstract, contact the ARVO Office at arvo@arvo.org.