An experimental study[39] that analyzed aqueous humor and plasma samples of 120 women with POAG found that the levels of interleukin-6 (IL-6), as an inflammation marker, and the expression of caspase-3 and poly ADP-ribose polymerase 1 (PARP-1), as apoptosis markers, were significantly higher in current smokers than in former- and nonsmokers (P < 0.05). Here, PARP1 is linked to open-angle glaucoma.