1. Optometry Department; Moorfields Eye Hospital NHS Foundation Trust; 162 City Road; London; EC1V 2PD; UK
2. National Institute for Health Research (NIHR) Biomedical Research Centre; UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust; London; UK
3. Glaucoma Service; Rotterdam Eye Hospital (Het Oogziekenhuis Rotterdam); Postbus 70030; 3000 LM; Rotterdam; the Netherlands