The collagen matrix in corneal pathology, and the effect of new therapies for loss of transparency and refractive status

Lead Research Organisation: Cardiff University
Department Name: Optometry and Vision Sciences

Abstract

The cornea is the transparent window at the front of the eye through which we see the coloured iris and black central pupil. It is made up mostly of a protein called collagen and forms part of the tough outer shell of the eye. Most of the outer shell is opaque and white in colour, but the cornea has evolved to transmit light. Evidently, the transparency of the cornea is absolutely essential for vision, and it is believed that the reason why the cornea, unlike all other collagen-containing tissues in the body, is transparent, is because of the special size and arrangement of the collagen and the special properties of the interspersed cells. One purpose of our proposed investigation is to discover precisely how the arrangement of the collagen and the properties of the cells allow the cornea to be transparent. We will then examine how certain treatments act to restore transparency where it has been lost. In addition to allowing light into the eye, the cornea is also curved in a special way to help focus the incoming light on the retina. Again, it is believed that aspects of the collagen organisation might influence this curvature and be important for corneal astigmatism and the recovery of good vision after corneal surgery (including new refractive surgeries such as LASIK). The research is to be carried out using a range of techniques, including synchrotron x-ray technology and several high powered microscopical methods. It will be carried out by a team of Biophysicists in Cardiff, but will involve a number of scientists and clinicians from around the world.

Technical Summary

The cornea is the main refractive component of the eye. Its dioptric power and efficiency in conveying an image to the retina free of astigmatism, both depend on its shape and surface topography. These, together with the cornea?s remarkable transparency, depend on the organisation of its constituent collagen molecules and fibrils, about which many questions remain unanswered. Corneal problems are a leading cause of visual impairment worldwide, and are an increasing drain on the NHS. Thus it is imperative to understand the reasons for transparency loss and for pathological and post surgical ectasia. Our work aims to do just this, and ascertain the structural basis for the restoration of corneal transparency and refractive status by a number of new therapeutic strategies. The objectives of this proposal are:
? To model corneal transparency at the cellular and fibrillar level and ascertain the potential of keratocyte stem cell therapy in the restoration of matrix structure and tissue transparency.
? To produce a full 3-D structural map of the healthy human cornea and understand the roles of specific lamella structures in determining its biomechanical properties, refractive status, pathological change and surgical treatment.
? To understand the cause of corneal ectasia and its treatment by ultraviolet crosslinking.
The principal method will be synchrotron x-ray scattering. This will be supplemented by microscopy (phase contrast, electron and multi-photon confocal), spectrophotometry, ocular coherence tomography, videokeratography, finite element analysis and computer modelling of light scattering.

Publications

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Akhtar S (2011) Role of keratan sulphate (sulphated poly -N-acetyllactosamine repeats) in keratoconic cornea, histochemical, and ultrastructural analysis. in Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie

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Boote C (2012) Quantitative assessment of ultrastructure and light scatter in mouse corneal debridement wounds. in Investigative ophthalmology & visual science

 
Description Influence on corneal surgery
Geographic Reach Multiple continents/international 
Policy Influence Type Influenced training of practitioners or researchers
 
Description Understanding corneal structure
Geographic Reach Multiple continents/international 
Policy Influence Type Influenced training of practitioners or researchers
 
Description BBSRC JSBI
Amount £112,093 (GBP)
Funding ID BB/J019879/1 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 07/2012 
End 12/2013
 
Description EPSRC Project Grant responsive mode
Amount £836,976 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start  
 
Description Fight for Sight Project Grant
Amount £149,950 (GBP)
Organisation Fight for Sight 
Sector Charity/Non Profit
Country United Kingdom
Start  
 
Description Royal Society/Wolfson Research Merit Award
Amount £75,000 (GBP)
Organisation The Royal Society 
Sector Charity/Non Profit
Country United Kingdom
Start  
 
Title Three dimensional image manipulation 
Description Developed methodologies and protocols for collection and presentation of 3D electron microscopy data sets 
Type Of Material Biological samples 
Year Produced 2013 
Provided To Others? Yes  
Impact A publication: Imaging three-dimensional tissue architectures by ion beam scanning electron microscopy. Nature Protocols 2011;6:845-858 (conducted under an EPSRC small facilities access award) 
 
Title XRD data analysis technique 
Description We have developed methods to analyse and display collagen orientation data collected in x-ray scatter patterns 
Type Of Material Improvements to research infrastructure 
Year Produced 2007 
Provided To Others? Yes  
Impact In the cornea, this method will allow finite element modelling of the cornea and this in turn will allow accurate predictions of the effects of corneal surgeries 
 
Title Elsheikh modelling of chick corneas 
Description Our quantitative x-ray data have been used to model the biomechanical behaviour of the cornea. 
Type Of Material Computer model/algorithm 
Year Produced 2008 
Provided To Others? Yes  
Impact Data helped explain the importance of the limbal annulus in maintaining corneal shape. This work was published. 
 
Title pinsky modelling of the healthy cornea 
Description Our quantitative x-ray data have been used to model the biomechanical behaviour of the cornea. 
Type Of Material Computer model/algorithm 
Year Produced 2009 
Provided To Others? Yes  
Impact Data helped explain the relationship between corneal structure and shape. The work was published. 
 
Description Collaboration with Bristol Zoo Gardens 
Organisation Bristol Zoo Gardens
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution We have collected x-ray scattering data from these corneas with the aim of learning more about the relationship between corneal structure, shape and function.
Collaborator Contribution Our collaborators provided post-mortem corneas from primates and other mammals.
Impact Meeting abstracts and publications. Multidisciplinary: Zoology, Biophysics, Biology
Start Year 2007
 
Description Collaboration with Farhad Hafezi (Geneva) 
Organisation Geneva University Hospitals
Country Switzerland 
Sector Hospitals 
PI Contribution We have collected x-ray scattering data from normal and keratoconus corneas that have been previously cross-linked using riboflavin and UVA.
Collaborator Contribution Prof Hafezi has been involved in the concept and design of collagen cross-linking studies involving keratoconus corneas. He also serves as an Honorary Overseas Consultant to the UK Cross-linking Consortium.
Impact Multidisciplinary publication (Ophthalmology, Biophysics, Biology): doi.org/10.1371/journal.pone.0022405 Farhad Hafezi is a confirmed guest speaker at our 2020 UK-Cross-linking Consortium meeting which will be held in May 2020, as part of the Royal College of Ophthalmology Annual Congress.
Start Year 2010
 
Description Collaboration with May Griffith 
Organisation Linkoping University
Department Regenerative Medicine
Country Sweden 
Sector Academic/University 
PI Contribution Prof Griffith has developed a biological artificial cornea which is in clinical trial. We will be investigating the ultrastructure of the constructs and what changes occur in vivo.
Collaborator Contribution They will provide the constructs. Joint collaborators in Aberdeen will implant the constructs into mouse eyes.
Impact Multiple publications on the structure and integration of the artificial constructs which have formed the basis of clinical trials: doi: 10.1038/s41536-017-0038-8 doi: 10.1016/j.actbio.2018.01.011 doi: 10.1016/j.actbio.2018.10.009.
Start Year 2012
 
Description Collaboration with Prof David O'Brart 
Organisation St Thomas' Hospital
Country United Kingdom 
Sector Hospitals 
PI Contribution Corneal cross-linking research is undertaken by Sally Hayes
Collaborator Contribution Prof O'Brart contributes to experimental study design in our corneal cross-linking research and helps to ensure that it has the maximum clinical relevance. He is also involved in the interpretation of cross-linking data.
Impact Multiple scientific publications: doi: 10.1016/j.jcrs.2015.10.004.; doi: 10.1167/iovs.17-22994.; doi.org/10.1016/j.exer.2016.10.014 Successful co-supervision of a PhD student leading to a published thesis (2018): Investigations into the potential effectiveness of new and existing corneal cross-linking therapies
Start Year 2010
 
Description Collaboration with Prof H. Serra Ciudad University, Argentina 
Organisation Ciudad University
Country Mexico 
Sector Academic/University 
PI Contribution We have gathered x-ray scattering and electron microscopy data from guinea pig corneas (provided by Prof. H. Serra) previously exposed to harsh environmental conditions similar to those experienced by humans in regions of the world where Climatic Droplet Keratopathy has been reported. Analysis of the data will determine if this is a suitable animal model for the disease.
Collaborator Contribution Our collaborators have provided us with corneas from a potential animal model for the human disease Climatic Droplet Keratopathy.
Impact Publications. Multidisciplinary: Ophthalmology, Biophysics, Biology
Start Year 2009
 
Description Collaboration with Prof J Hjordtal (Aarhus University) 
Organisation Aarhus University Hospital
Department Department of Ophthalmology
Country Denmark 
Sector Hospitals 
PI Contribution Ultrastructural analysis of rare corneal graft tissue
Collaborator Contribution Provided tissue and clinical expertise
Impact ARVO abstracts. Multidisciplinary: Ophthalmology, Biophysics, Biology
Start Year 2009
 
Description Collaboration with Prof. A Jun and Prof W Stark (Johns Hopkins) 
Organisation Johns Hopkins Medicine
Department Wilmer Eye Institute
Country United States 
Sector Academic/University 
PI Contribution Initiated collaboration on animal models of Fuch's Dystrophy
Collaborator Contribution Providing tissue and clinical expertise
Impact ARVO abstract
Start Year 2011
 
Description Collaboration with Prof. J. Funderburgh in University of Pittsburgh Medical Centre 
Organisation University of Pittsburgh Medical Center (UPMC)
Country United States 
Sector Hospitals 
PI Contribution collagen ultrastructural x-ray studies of scarred corneas treated with stromal stem cells
Collaborator Contribution Provided wounded mouse corneas for stem cell baseline studies
Impact International Collaboration Award-Early Career Researcher 2007/08, Cardiff University. Funding was allocated to Dr. Christina Kamma-Lorger to visit collaborative lab in in Pittsburgh University for 4 weeks, to receive training in corneal stem cell techniques and establishing a new collaboration (2300GBP)+ publications (see list). Multidisciplinary: Ophthalmology, Biophysics, Biology, Molecular Biology
Start Year 2007
 
Description Collaboration with Profs Nguyen/Quigley at Johns Hopkins University 
Organisation Johns Hopkins Medicine
Department Wilmer Eye Institute
Country United States 
Sector Academic/University 
PI Contribution Initiated x-ray studies of glaucoma corneas and scleras to provide data for numerical models
Collaborator Contribution Provided mechanical data of normal and glaucoma corneas and scleras and incorporated our x-ray data into finite element simulation to model ocular behaviour
Impact Presented the first X-ray data from human scleras at ARVO in 2010 - impacting on the ocular biomechanics and clinical communities concerned with glaucoma - leading to project grant funding from Fight For Sight and NIH. Multidisciplinary: Ophthalmology, Biophysics, Biology, Engineering
Start Year 2009
 
Description Diamond 
Organisation Diamond Light Source
Country United Kingdom 
Sector Private 
PI Contribution Data collection at the Diamond Light Source and equipment development . In partnership with Diamond Light Source, Dr James Bell is leading the development of a biomechanical testing platform that will allow a wide-range of scientists to perform simultaneous x-ray scattering/biomechanical testing on a range of connective tissues.
Collaborator Contribution Assisting with data collection and equipment development. Administration and publicity of the Biomechanics Facility User Network
Impact Our ongoing collaboration with DLS has resulted in a large number of publications, the most recent of which are: doi: 10.1016/j.actbio.2017.11.015 doi: 10.1098/rsif.2017.0062. doi: 10.1167/iovs.16-21358. The formation of a Biomechanics Facility and User Network at Diamond Light Source (https://www.diamond.ac.uk/Instruments/Soft-Condensed-Matter/small-angle/I22.html). Led by James Bell, the multi-disciplinary user network (comprising connective tissue researchers, physicists and engineers) are contributing to the design of a general purpose miromechanical testing platform that will be made freely available to scientists during their beamtime at Diamond Light Source to enhance connective tissue and materials-based research.
Start Year 2007
 
Description Dr Ahmed ElSheikh 
Organisation University of Dundee
Country United Kingdom 
Sector Academic/University 
PI Contribution Modelling corneal structure and biomechanics. Our structural data is being used to model corneal biomechannical behaviour. We are also working together to simultaneously monitor changes in corneal structure and stress-strain behaviour by covering corneas with a fine-particle speckle pattern and then collecting x-ray scattering data at the same time as collecting images of the corneal surface on spatially oriented cameras.
Collaborator Contribution Allowed us to progress the biomechanical implications of our structural data
Impact Multiple publications as co-authors: doi:10.1098/rsif.2010.0108; doi: 10.1016/j.actbio.2017.11.015.; doi:10.1016/j.jmbbm.2014.11.006
Start Year 2008
 
Description Professor C. Inglehearn 
Organisation University of Leeds
Country United Kingdom 
Sector Academic/University 
PI Contribution We have used our structural data to help understand the changes in eye shape in genetically mutated chicks
Collaborator Contribution Allowed us to explore the relatioionship between genetics, structure and eye shape
Impact Collaboration formed part of a following grant and publications are listed under G0600755
Start Year 2006
 
Description American Academy for the Advancement of Science Conference, Chicago 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact 30 minute lecture to a public audience.

Disseminated our work to a public audience at one of the most prestigious meetings.
Year(s) Of Engagement Activity 2009
 
Description American Academy for the Advancement of Science Press Conference, Chicago 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact International press conference to about 40 journalists

A podcast and a BBC TV interview (listed separately) and a very large number of web sites reporting our work. e.g.: UK leading the way in corneal research http://www.diamond.ac.uk/Home/Media/LatestNews/13_02_09b.html UK leading the way in corneal research (February 17, 2009) http://ukinusa.fco.gov.uk/en/newsroom/?view=News&id=13691933 Intense x-rays advance corneal research. http://www.nkcf.org/research/research-update/101-x-ray-advance-corneal-research.html UK leading the way in corneal resear
Year(s) Of Engagement Activity 2009
URL http://www.diamond.ac.uk/Home/Media/LatestNews/13_02_09b.html
 
Description Article in Projects Magazine 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Dissemination to the leading research and development magazine in the areas of science and technology http://www.projectsmagazine.eu.com/magazines

Raised the profile of our medical technology
Year(s) Of Engagement Activity 2010
 
Description BBC Radio coverage 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact BBC Radio Oxford interview (Malcolm Boyden Show) about my research parts of which were broadcast in news bulletins throughout the morning of 26th October 2009

Raised the profile of our vision research
Year(s) Of Engagement Activity 2009
 
Description BBC TV coverage 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Was filmed and interviewed at Diamond Synchrotron by BBC Oxford

Was braodcast as news report on BBC Oxford TV - informing public of our research
Year(s) Of Engagement Activity 2009
 
Description Earth Sky Podcast 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Interview

Braodcast as Podcast on internet - increasing public awareness of our research. Keith Meek seeks to understand the workings of the eye's cornea http://www.earthsky.org/interviewpost/health/keith-meek-reveals-patterns-inside-the-eye%e2%80%99s-cornea
Year(s) Of Engagement Activity 2009
URL http://www.earthsky.org/interviewpost/health/keith-meek-reveals-patterns-inside-the-eye%e2%80%99s-co...
 
Description Lecture to young collage students, Madrid 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Postgraduate students
Results and Impact Key-note speaker in the course "Refractive surgery and quality of vision" Madrid 2008. About 30 students attended. Sparked questions and discussion.

Raised the profile of our vision research on an international stage
Year(s) Of Engagement Activity 2008
 
Description Regular presentations to health care professionals 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Invited speaker

Raised the profile of vision research
Year(s) Of Engagement Activity 2006,2007,2008,2009,2010,2011
 
Description School work experience 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? Yes
Type Of Presentation Workshop Facilitator
Geographic Reach Local
Primary Audience Schools
Results and Impact Te activity encouraged these children to choose Physics at university and hopefully will make them want to move into Biophysics later.

Positive feedback from students and schools so there have been continuing requests for us to take on students in following years
Year(s) Of Engagement Activity 2011,2012,2013,2014,2015