Objective: Glaucoma has been estimated to affect 2.1% of the population aged 40 years and over and given the clinical impact of glaucoma, it is important to evaluate the potential economic burden of the disease. The aims were to estimate the direct medical costs of glaucoma in Sweden and also to investigate the hypothesized cost drivers; intraocular pressure (IOP), amount of visual field damage estimated by the MD, change of MD (ÄMD) and pseudoexfoliation syndrome (PEX). Methods: The study was based on 583 Swedish patients with open-angle glaucoma and manifest field loss followed between 4.5 and 9.25 years. Data on MD, IOP, PEX, medical resources, and low-vision centre visits were collected and organized in three-month periods. The average baseline MD was -11.7 dB and initial values of average IOP, age were 22.5 mmHg, and 71 years, respectively. All used resources were multiplied with its respective unit costs to calculate the medical costs for each patient. Cost regressions were estimated with a multivariate population-averaged panel data model. Results: Average annual medical cost/patient of glaucoma was estimated at €627/year. Independent cost drivers were IOP (p<0.001), MD (p<0.001), ÄMD (p=0.03) and PEX (p<0.001). Prevalence of PEX was associated with 21% higher costs. Each one-unit increase in mmHg (IOP), decrease in dB (MD) or ÄdB/year (ÄMD) increased costs by 2.9 %, 1.2% and 5.7%, respectively. Patients that had visited a low-vision centre at least once had 46% higher annual costs than the average patient. Conclusion: MD, ÄMD, IOP, and PEX are all drivers of medical cost of glaucoma in Sweden. Further, the variables are predicting cost independently of each other.