Department of Ophthalmology (JX), Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts; Division of Gastroenterology, Hepatology, and Nutrition (YJZ) and Department of Ophthalmology (EG, THD, EDG), Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Ophthalmology (THD, EDG), Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts; and Picower Institute for Learning and Memory (EDG), Massachusetts Institute of Technology, Cambridge, Massachusetts.

Address correspondence to Eric D. Gaier, MD, PhD, Department of Ophthalmology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115; E-mail: [email protected]

Supported by NIH grants K08 EY030164 (E. D. Gaier) and K08 EY031759 (T. H. Dohlman).

The authors report no conflicts of interest.