The Jidong Eye Cohort Study: objectives, design, and baseline characteristics

To describe the objective, design and baseline characteristics of the Jidong Eye Cohort Study (JECS), a community-based cohort in China based on etiology, imaging and biomarkers. The JECS will clarify the pathogenesis of visual impairment and status of ocular indicators in the occurrence and progression of cardio-cerebrovascular and neurological diseases.

Between August 2019 and January 2020, the JECS recruited consecutive participants aged 18 years and older from the Jidong communities in China. The demographic and clinical characteristics were collected by trained site personnel via face-to-face interviews. The relevant biological samples were also collected. The participants underwent comprehensive ophthalmic examination, such as retinal photography and optical coherence tomography (OCT) angiography. The following outcomes were measured annually: ocular vascular abnormality, optic nerve degeneration, cardiovascular diseases (CVD) and neurological diseases. The study will be performed until 2024.

Among 3377 participants, the average age was 45.0 ± 12.5 years and 1809 (53.6%) were women. Hypertension occurred in 825 individuals (25.0%), diabetes in 258 (7.7%), hyperglycemia in 474 (14.2%), and a CVD history in 100 (3.0%). The mean best-corrected visual acuity was 0.1 logMAR in the recruited subjects. The average OCT signal index was 8.2 ± 1.2. Additionally, the mean vessel densities for the entire measured area were 46.4% and 50.8% for the superficial and deep vascular complex, respectively. Mean area and perimeter of foveal avascular zone was 0.3 mm² and 2.3 mm.

The JECS is a large community-based prospective cohort in North China. Rich data collected from this study will provide the opportunity to identify risk factors, imaging, and biomarkers of visual impairment (either ocular vascular anomalies or optic nerve degeneration) and to evaluate their associations with CVD and neurological diseases.