Introduction/Objective. Fas ligant (FasL) induces apoptosis when interacting with the Fas-receptor. The aim was to determine the concentration of soluble Fas (sFas) and FasL (sFasL) in the aqueous humor of open-angle glaucoma patients, and establish a connection between these markers of apoptosis and the parameters of structural and functional glaucoma damage. Methods. This study examined 88 aqueous humor samples; 35 primary open-angle glaucoma with elevated intraocular pressure (POAG-HTG) patients, 24 open angle pseudoexfoliative glaucoma patients (XFG) and 29 patients with senile cataract (CAT). The concentration of sFas and sFasL was determined by commercial ELISA tests in the aqueous humor. Results. The conducted study showed that aqueous humor sFas concentration was the highest in XFG (720.14 ? 167.39 pg/ml), and slightly lower in POAG-HTG (713.43 ? 162.69 pg/ml), than in cataract patients (632.46 ? 217.11 pg/ml), without statistical significance. There was a significant negative correlation of sFas concentration and RNFL Inf thickness in POAG-HTG (p < 0.05). The concentration of sFasL was the lowest in POAG-HTG (9.28 ? 0.551 pg/ml), higher in XFG (9.45 ? 0.61 pg/ml; p = 0.0566), and the highest in the cataract group (9.48 ? 0.73 pg/ml). A negative correlation of sFasL and MD in the POAG-HTG, and a negative correlation with RNFL Sup in the XFG were significant. Conclusion. sFasL has an active role in the regulation of the inflammatory process in glaucoma. sFas and sFasL, as markers of apoptosis, are associated with the parameters of structural, RNFL thinning, and functional glaucoma damage, namely visual field defects.