1. From the Departments of Ophthalmology and Visual Sciences and
2. Pediatrics, Case Western Reserve University and
3. From the Departments of Ophthalmology and Visual Sciences and 3University Hospitals, Cleveland, Ohio;
4. Department of Pathology, University of Texas Medical Branch, Galveston, Texas; and
5. Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden.