HPGDS and exfoliation syndrome: Because of the role of GSTs in inactivating endogenous end products formed as secondary metabolites during oxidative stress, we decided to compare the distribution of GSTM1 and GSTT1 polymorphisms in Saudi patients with POAG, pseudoexfoliation glaucoma (PEG), and primary angle-closure glaucoma (PACG) to the distribution in matching healthy controls.