Abstract: Objective To describe the characteristics of lens vault (lens vault, LV) in people over 45 years old in Beijing Eye Study and explore its correlation with primary angle closure glaucoma (PACG). Design Cross-sectional study. Participants 2792 subjects of 45-years old or more in 5-year followed population of Beijing Eye Study. Methods Detailed eye examinations were performed for the subjects, including refractive measurement, intraocular pressure (non-contact tonometer), digital anterior segment photography of slit lamp after mydriasis, and axis of the eye measurement of academic parameters (Lenstar) and fundus photography. The Heidelberg anterior segment OCT was used to take pictures and the LV (the vertical distance between the anterior pole of the lens and the horizontal line of the two scleral processes) was measured through the built-in software. The content of the questionnaire involved smoking history, drinking history, diabetes and hypertension and other medical history. Logistic regression was used to explore the correlation between LV and PACG, and odds ratios (OR) and 95% confidence interval (CI) were used to assess the strength of the association. Main Outcome Measures LV, OR value and 95%CI. Results The average LV level of people over 45 years old in Beijing Eye Study was 0.43±0.26 mm, the average LV level of men was 0.38±0.28 mm, and that of women was 0.45±0.28 mm (t=4.76, P<0.001). The LV levels of people 45~54 years old, 55~64 years old, 65~74 years old and ≥75 years old are 0.33±0.26 mm, 0.42±0.27 mm, 0.48±0.29 mm and 0.58±0.29 mm, respectively, increasing with the increasing of age (F=7.84, P<0.001). The LV levels of myopia, emmetropia, and hyperopia were 0.26±0.31 mm, 0.43±0.26 mm, and 0.56±0.26 mm, respectively. As the refractive status changed from nearsightedness to farsightedness, the LV level also showed an upward trend (F=4.86, P<0.001). The average LV levels of healthy people and PACG patients were 0.42±0.28 mm and 0.84±0.25 mm, respectively (t=5.66, P<0.001). Logistic regression showed the correlation between LV and PACG(OR=1.022; 95% CI: 1.005, 1.040). Conclusion The average LV value of healthy people over 45 years old in Beijing area is 0.42±0.28 mm. LV increases with age. Women's LV value is higher than that of men, and the LV value of hyperopia is higher than that of myopia. larger LV is a risk factor for PACG. (Ophthalmol CHN, 2021, 30: 200-203)

Key words: lens vault, population, anterior segment OCT, angle-closure glaucoma