Abstract:

Objective To investigate the 5-year changes of retinal vascular diameters in elderly population (aged 40 or more) in Beijing and analyze the related factors. Design Cohort study. Participants 506 subjects were selected randomly from the 5-year follow-up population of Beijing Eye Study. Methods Quantitative measurement software (Singapore I Vessel Assessment, SIVA 3.2) was used to measure the parameters of retinal vascular diameters in color fundus photographs in 506 subjects. One eye of each participant was randomly selected. The region from 0.5~1 PD away from the disc margin is zone B, 0.5~2 PD away from the disc margin is zone C. The changes of the retinal vascular diameters were compared during the baseline and 5-year follow-up of the subjects and the related factors were analyzed. Main Outcome Measures Central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), arteriole-to-venular ratio(AVR), mean width arteriole (MWa), mean width venule (MWv), standard deviation width arteriole (STDWa) and standard deviation width venule (STDWv), length-diameter ratio arteriole (LDRa) and length-diameter ratio venule (LDRv) in zone B and C. Results 348 (68.9%) of the 506 subjects in this study have clear evaluable fundus photographs at baseline and 5-year follow-up. Compared with baseline, CRAE and CRVE in Zone B have no significant change in 5 years(P>0.05); CRAE and CRVE in Zone C increased significantly (P=0.001); AVR in zone B and C have no significant change (P>0.05). 5 years later, the MWa and MWv in zone B and C decreased significantly (P=0.000); STDWa and STDWv in zone B increased significantly (P<0.05); STDWa and STDWv in zone C have no significant change (P>0.05). LDRa and LDRv increased significantly (P=0.000). Multivariate analysis showed, the change of MWa was age-related(r=0.105, P=0.041); the changes in CRVE (r=5.733, P=0.029) and MWv (r=3.210, P=0.020) were associated with smoking. The change of STDWv was correlated with hyperlipidemia(r=-0.204, P=0.023); the change in LDRv was associated with coronary heart disease(r=5.088, P=0.044). Conclusion In general, retinal artery and vein gradually become thinner and longer in 5 years; AVR was relatively stable. Changes in retinal vascular diameter were associated with smoking, hyperlipidemia, coronary heart disease and other systemic factors.

Key words: retinal vessels, morphology, vascular diameter