1. From the Gullstrand Lab, Ophthalmology, Department of Neuroscience, Uppsala University, Uppsala, Sweden;
2. From the Gullstrand Lab, Ophthalmology, Department of Neuroscience, Uppsala University, Uppsala, Sweden; the 2St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden;
3. the Department of Statistics, University of California at Los Angeles, Los Angeles, California; and
4. the Department of Veterinary and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska.