Abstract:  Objective To compare age-related changes of the macular vessel density and perfusion density with optical coherence tomography angiography (OCTA) measurements in normal adults between under and over beyond 40 years old. Design Cross-sectional study. Participants One hundred and forty-two subjects (76 males, aged 45.50±12.65 years) were recruited from October 2020 to December 2020 in the Beijing Tongren Health Center. Methods All subjects were divided into 18-39 years old group and ≥40 years old group. Visual acuity, spherical equivalent (SE), intraocular pressure, slit lamp microscope, color fundus photography and 6 mm×6 mm macular OCTA were conducted for all eyes. The data of right eye was analyzed. Simple regression analysis determined the association between age vs. macular vessel density, perfusion density and area of FAZ. Main Outcome Measures Macular vessel density, perfusion density and the area of FAZ. Results The macular of total vessel density was (17.49±1.15) mm-1 in age beyond 40 years group, which was significantly lower than that of the age under 40 years (17.88±9.76) mm-1(P=0.037). The outer-ring of macular vessel density in age beyond 40 years group was (17.83±1.12) mm-1, which was significantly lower than that of the age under 40 years (18.24±1.00) mm-1. There were no significant differences in other macular vessel density, perfusion density and the area of FAZ between the two groups (all P＞0.05). The macular total vessel density decreased by 0.02 mm-1 (t=-2.34, P=0.021) per year with increasing age. The outer-ring of macular vessel density decreased by 0.02 mm-1 (t=-2.42, P=0.017) per year with increasing age. Age have no impact on other macular vessel density parameters, perfusion density and the area of FAZ(all P＞0.05). Conclusion Macular vessel density shows age-related decrease with significant drop in the 4th decade. These factors should be considered carefully if using OCTA to measure macular vessel flow. （Ophthalmol CHN, 2022, 31: 125-129）

Key words: optical coherence tomography angiography, age