[1] Univ Manchester, Manchester Royal Eye Hosp, Dept Ophthalmol, Manchester M13 9WH, Lancs, England
[2] Univ Manchester, St Marys Hosp, Dept Med Genet, Manchester M13 0JH, Lancs, England
[3] St Marys Hosp, Reg Genet Serv, Manchester M13 0JH, Lancs, England
[4] Cardiff Univ, Dept Optometry & Vis Sci, Cell & Mol Biol Unit, Cardiff CF10 3YJ, S Glam, Wales
[5] Univ Manchester, Sch Biol Sci, Wellcome Trust Ctr Cell Matrix Res, Manchester M13 9JH, Lancs, England