1. Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK
2. UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
3. Royal Surrey County Hospital, Egerton Road, Guildford, Surrey GU2 7XX, UK
4. Bnai Zion Medical Center, 47 Golomb Road, 31048 Haifa, Israel