1. Department of Eye and Vision Science, University of Liverpool, Liverpool L7 8TX, UK.
2. Institute of Veterinary Science, University of Liverpool, Liverpool L3 5RF, UK.
3. National Specialist Ophthalmic Pathology Service, Royal Liverpool University Hospital, Liverpool L7 8XP, UK.
4. Institute of Ophthalmology, University College London, London EC1V 9EL, UK.
5. Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK.