1. From the Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania; the
2. Department of Ophthalmology, Howard Hughes Medical Institute, University of Iowa Hospitals and Clinics, Iowa City, Iowa; the
3. Usher Syndrome Center, Boys Town National Research Hospital, Omaha, Nebraska; and the
4. Department of Otolaryngology, University of Miami, Miami, Florida.