The aim of the present study was to evaluate the effect of latanoprost monotherapy on the aqueous humour concentrations of TGF-beta1, MMP-2, TIMP-2, MMP-9 and gelatinolytic activity in patients treated for exfoliative glaucoma (XFG). Aqueous samples from 50 XFG patients treated with latanoprost and 50 age-matched XFG patients treated with timolol were collected during phacoemulsification cataract surgery. The concentrations of TGF-beta1, MMP-2, TIMP-2, MMP-9 and gelatinase activity were determined by commercial immunoassays. The mean active TGF-beta1 concentration in the aqueous was significantly lower in XFG patients treated with latanoprost compared with those treated with timolol (3.1 +/- 0.65 vs 13.4 +/- 1.5 pg ml(-1)); (P = 0.0014). The mean total MMP-2 concentration was lower in latanoprost treated patients (31.75 +/- 3.8 vs 81.5 +/- 7.2 ng ml(-1)); (P < 0.0001). The TIMP-2 concentration was also lower in XFG-latanoprost treated patients (73.8 +/- 6.81 vs 101.28 +/- 7.29 ng ml(-1)); (P = 0.0096). Latanoprost monotherapy has a marked effect on the aqueous concentration of TGF-beta1, MMP-2 and TIMP-2 in XFG patients. A better understanding of its effect on the pathobiology of the disease may lead to its earlier use in the disease process to prevent progression from XFS to XFG.