[1] UCL, Populat Policy & Practice Res & Teaching Dept, Great Ormond St Inst Child Hlth, 30 Guilford St, London WC1N 1EH, England
[2] UCL, Great Ormond St Inst Child Hlth, Ulverscroft Vis Res Grp, London, England
[3] Great Ormond St Hosp Sick Children, NHS Fdn Trust, London, England
[4] Kings Coll London, Sch Life Course Sci, Sect Ophthalmol, London, England
[5] Kings Coll London, Sch Life Course Sci, Dept Twin Res & Genet Epidemiol, London, England
[6] UCL, Inst Ophthalmol, London, England
[7] NIHR Moorfields Biomed Res Ctr London, London, England