1. Department of Otorhinolaryngology, Royal Glamorgan Hospital, Ynysmaerdy, Llantrisant CF72 8XR, UK
2. Department of Otorhinolaryngology, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK
3. Department of Ophthalmology, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK
4. Department of Cellular Pathology, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK