1. From the Department of Small Animal Clinical Sciences (MM Smith), Virginia-Maryland Regional College of Veterinary, Medicine, Virginia Tech, Blacksburg, VA, 24061; Animal Eye, Care Center (EM Smith), 9043 Gaither Road, Gaithersburg. MD, 20877; Eye Care Clinic for Animals (La Croix), 1892 East, Fort Union Boulevard, Salt Lake City, UT, 84094; and, the University of Glasgow Veterinary School, Division of Small, Animal Clinical Studies (Mould), Bearsden Road, Bearsden, Glasgow G61 1QH