[1] Karolinska Univ Hosp, Dept Paediat Ophthalmol & Strabismus, St Erik Eye Hosp, S-14186 Stockholm, Sweden
[2] Karolinska Inst, Dept Clin Neurosci, Stockholm, Sweden
[3] Univ Manchester, Manchester Acad Hlth Sci Ctr, Manchester, Lancs, England
[4] Johannes Gutenberg Univ Mainz, Dept Ophthalmol, Mainz, Germany
[5] Helsinki Univ Eye Hosp, Dept Paediat Ophthalmol, Helsinki, Finland
[6] Univ Minnesota, Dept Ophthalmol, Minneapolis, MN 55455 USA
[7] Univ Minnesota, Dept Pediat, Minneapolis, MN 55455 USA