AIM: To evaluate the mid-term effects of topical latanoprost 0.005% on vessel density (VD) of the bulbar conjunctiva using anterior segment optical coherence tomography angiography (OCTA). METHODS: Thirty-four eyes of 21 patients and 18 eyes of 9 healthy subjects were recruited as the treatment and control groups, respectively. The treatment group was instructed to apply generic latanoprost 0.005% once daily at night, while the control group received no medication. Anterior segment OCTA was performed on all eyes at baseline, 3wk, and 12wk after initiation of latanoprost. The superficial bulbar conjunctival VD was measured in the superior, inferior, temporal, and nasal quadrants. A linear mixed model was used to compare the change in the VD between groups. RESULTS: The change in the VD was not different between groups in temporal, and nasal quadrants at 3-week and 12-week time points. The VD in the superior bulbar conjunctiva was significantly increased after 12wk (P=0.029) while the change from baseline after 3wk was not different between groups (P=0.218). After adjustment for age and gender superior hemi (P=0.006) and center (P=0.016) of the inferior quadrant of bulbar conjunctiva showed increased VD after 12wk. CONCLUSION: The trend of changes in the superior and inferior conjunctival VD is increased following topical latanoprost administration and these changes can be quantified using anterior segment OCTA.