1. Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G-1Y6;
2. Theratechnologies, St. Laurent, Quebec H4S-2A4; and
3. Departments of Pediatrics, Ophthalmology, and Pharmacology, Research Center of Hôpital Ste. Justine, Montreal, Quebec H3T-1C5, Canada; and
4. University of California, San Francisco, California 94143