Primary open-angle glaucoma (POAG) is the most common type of glaucoma. Corneal thickness is a biomarker for glaucoma genotype, that was significantly thinner in patients receiving topical antiglaucoma, beta-blockers, prostaglandin analogues, carbonic anhydrase inhibitors, and alpha-2 agonists. This study was an analytic observational study with cross sectional design to analyze corneal thickness in patients with POAG who received glaucoma medication. The subjects were POAG patients that received glaucoma medication for more than 6 months. Corneal thickness measurements were performed using Anterior Segment-Ocular Coherence Tomography (AS-OCT). From 60 POAG subjects, the mean age was 54.60±10.021 years old and female subjects was accounted for 55%. From total of 75% subjects who received multi-therapy treatment, most type of treatments were beta blockers and prostaglandin analogues. The average duration of treatment was 21.97±13.062 months. This study found statistically significant and negative correlation in superior paracentral (p=0.037, r-0.231) and superonasal paracentral (p=0.029, r- 0.241) corneal thickness with the duration of treatment. The study revealed that there was a significant relationship between the use of beta blockers and prostaglandin analogues. The relationship between corneal thickness and duration of treatment was found, which was thinning of corneal thickness in all areas but statistically, a significant relationship was only found in the superior paracentral, superonasal paracentral, and inferonasal paracentral areas. There was a significant correlation between the type, amount, and duration of treatment on central corneal thickness. Anterior segment OCT might be helpful to evaluate the effect of antiglaucomatous medications on corneal epithelial thickness.