AIM:To assess the effects of the fixed combination of 0.005% latanoprost and 0.5% timolol (FCLT) vs their individual components for primary open angle glaucoma (POAG) and ocular hypertension (OHT).METHODS:After searched PubMed, EMBASE, the Cochrane Library and SCI, all randomized controlled clinical trials (RCTs) and cross-over studies were included. The control groups were the mono therapy or the concomitant therapy of latanoprost and timolol. The outcomes were visual field defect, optic atrophy, mean intraocular pressure (IOP) and IOP fluctuation. The analysis was carried out in RevMan version 5.1 software.RESULTS:The post-intervention mean IOP of FCLT was significantly lower compared to timolol [mean difference (MD) -2.92, 95%CI -3.28 to -2.55, P<0.00001] and latanoprost (MD -1.11, 95%CI -1.51 to -0.72, P＜0.00001). The post-intervention IOP fluctuation was also significantly lower compared to timolol (MD -0.88, 95%CI -1.23 to -0.53, P<0.00001) and latanoprost (MD -0.63, 95%CI -1.04 to -0.22, P=0.002). The mean IOP was higher in FCLT morning dose group than the one in unfixed combination of 0.005% latanoprost and 0.5% timolol (UFCLT) (MD 1.10, 95%CI 0.81 to 1.39, P<0.00001). Otherwise, there was no difference between FCLT evening dose group and UFCLT (MD 0.34, 95% CI -0.01 to 0.69, P=0.06). There was no statistical difference for the incidence of visual field defect and optic atrophy between FCLT and the monotherapy of components.CONCLUSION:A better IOP lowering effect has been demonstrated for FCLT compared to the mono therapy of components. The IOP lowering effect was worse for FCLT morning dose and almost same for FCLT evening dose compared to the UFCLT. We need more long-term high quality RCTs to demonstrate the outcomes of visual field defect and optic atrophy.