[1] Univ Regensburg, Dept Paediat Ophthalmol Strabismol & Ophthalmogen, D-8400 Regensburg, Germany
[2] Univ Passau, Bavarian Res Ctr Knowdlege Based Syst ForWiss, D-8390 Passau, Germany
[3] Alberta Childrens Prov Gen Hosp, Dept Ophthalmol, Calgary, AB, Canada