1Manchester Royal Eye Hospital Manchester M13 9WH, UK
2Department of Neuroradiology Manchester Royal Infirmary Manchester, UK
Correspondence to: B Leatherbarrow, Tel: 0161 276 5569 Fax: 0161 272 6618 E-mail: bollin@mighty-micro.co.uk
Eye (2002) 16, 800-802. doi:10.1038/sj.eye.6700212