CYP1B1 and primary congenital glaucoma: Variants in the CYP1B1 gene are most commonly associated with primary congenital glaucoma (PCG) but have also been identified in other congenital eye diseases, such as congenital ectropion uvea (CEU), congenital corneal opacification (CCO), Axenfeld–Rieger Syndrome (ARS), sclerocornea, and aniridia (Figure 1) [1,2,3,4,5,6].