- Correspondence to: M D Knudtson University of Wisconsin-Madison, School of Medicine and Public Health, Department of Ophthalmology and Visual Sciences, 610 North Walnut Street, 4th Floor WARF, Madison, WI 53726-2336, USA;
- Accepted September 11, 2006
- First published October 31, 2006.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.