[1] Children's Hospital of Cologne,
[2] Department of Paediatrics,undefined
[3] Amsterdamerstrasse 59,undefined
[4] D-50735 Cologne,undefined
[5] Germany,undefined
[6] Tel.: +49-221-7774596,undefined
[7] Fax: +49-221-7774330,undefined
[8] Department of Paediatric Ophthalmology,undefined
[9] Children's Hospital of Cologne,undefined
[10] Cologne,undefined
[11] Germany,undefined