To report the updated prescription trend of antiglaucoma medications, the dose-based prescription of a glaucoma medication in Japan in the fiscal year 2019 was aggregated by using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) Open data. Of the 100 most frequently prescribed topical medications for outpatients from out-hospital pharmacies, 32 glaucoma medications were identified. This year, 150.8 million ml of glaucoma medications prescribed accounted for 12.3% of the total prescription dose (1.3 billion ml). The dose was the largest with prostaglandin FP2α agonist (PGF2α), followed by the fixed-dose combination (FDC) of β-blocker and carbonic anhydrase inhibitor (β + CAI) and α2-agonist. Prescription doses peaked at 75–79 years old for all medication classes, except for prostaglandin EP2 agonist of that peaked 10 years younger age class than other medications. The prescription dose was larger in women (55.3%) than men (44.7%), single medication formulation (71.2%) than FDC (28.8%), and brand-name (85.2%) than generic (14.8%). By multivariate analysis, prescription doses were affected by roles of the sex (p = 0.0066) and brand-name or generic (p = 0.032), but not by single medication formulation or FDC (p = 0.67); age was the most remarkable parameter for the difference in prescription dose (p < 0.0001). Dose-based anti-glaucoma medication prescription was analyzed using the government-provided most recent database on a national scale. The results provide the up-to-date real-world glaucoma medication prescriptions where the country has the highest aging rate in the world.