CNR1 and Schnyder corneal dystrophy: Preclinical studies suggest that cannabinoids may ameliorate pain and address the underlying pathophysiologic changes in SCD.10,11 Intraperitoneal CP55,940, a synthetic nonselective high affinity agonist of cannabinoid receptors 1 and 2 significantly reduced chronic and hypoxia–reoxygenation-evoked pain in HbSS-BERK sickle mice.10,11,12 These mice closely recapitulate clinical and pathophysiological features of SCD.