Abdallah A Ellabban1,2, Richard Barry1, Ahmed A B Sallam1,3. 1. Department of Ophthalmology, Gloucestershire Hospitals NHS Foundation Trust, Gloucester Royal Hospital, Gloucester, UK. 2. Department of Ophthalmology, Suez Canal University, Ismailia, Egypt. 3. Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA.