1. Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minn.
2. Department of Otolaryngology-Head and Neck Surgery, New York-Presbyterian Hospital Columbia University Medical Center, New York, N.Y.
3. Department of Ophthalmology, University of California–San Francisco, San Francisco, Calif.
4. Ophthalmology Section, Surgical Service, San Francisco Veterans Affairs Medical Center, San Francisco, Calif.