Abstract: Objective To assess whether trans-lamina cribrosa pressure difference (TLCPD) is associated with glaucoma in a population-based setting. Design Population-based cross-sectional study. Participants 6830 Han people aged 30 years or older from 13 villages of Yongnian County were recruited. Methods All participants underwent questionare, comprehensive eye examinations and physical examinations. Ocular examination included measurement of visual acuity (VA), intraocular pressure, anterior and posterior segment examinations, visual field testing, and anterior segment, fundus and optic disc photography/imaging. Physical examination included measurement of height and weight, blood pressure, electrocardiogram, glucose, lipid levels, urea nitrogen and creatinine etc. Optic disc parameters were obtained using HRT II. Based on a previous study with lumbar cerebrospinal fluid pressure (CSFP) measurements, CSFP was calculated as CSFP (mmHg)=0.44×BMI (kg/m2) + 0.16×DBP (mmHg) -18×Age (Years) -1.91. TLCPD was intraocular pressure (IOP)-CSFP. The associations of systemic parameters, ocular parameters and TLCPD or CSFP were assessed using simple and multiple regression analysis. The relationship between TLCPD and prevalence of POAG or the amount of glaucomatous damage were analyzed. Main Outcome Measures Presence of POAG, presence of primary angle-closure glaucoma (PACG), CSFP, TLCPD. Results Measurements of blood pressure, body height, and weight were available for 6450 (87.5%) subjects. In sixty-seven patients with primary open-angle glaucoma (POAG) as compared with non-glaucomatous individuals, estimated CSFP was lower (10.2±3.7 mmHg versus 12.0±3.4mmHg; P<0.001) and estimated TLCPD was higher (6.4±4.2mmHg versus 2.9±3.7mmHg; P<0.001). In multivariate analysis, higher estimated TLCPD (P<0.001; standardized correlation coefficient β: 0.08; correlation coefficient B: 4.12; 95% Confidence Interval (CI): 2.24, 6.02) and lower estimated CSFP (P=0.01; β: -0.05; B: -2.37; 95%CI: -4.23, -0.51) were associated with higher prevalence of POAG. If the parameters of TLCPD and IOP were include in the model, presence of POAG was significantly associated with higher estimated TLCPD (P<0.001; odds ratio (OR): 1.29; 95%CI: 1.20, 1.38) but not with IOP (P=0.32). The association between larger rim area and lower estimated TLCPD (P=0.002; β: -0.03; B: -0.003; 95%CI: -0.005, -0.001) was stronger than the association between larger rim area and smaller IOP (P=0.398). Presence of thirty-two patients with primary angle-closure glaucoma (PACG) was significantly associated with IOP (P=0.02; OR: 1.38; 95%CI: 1.05, 1.71) but not with estimated TLCPD (P=0.46). Conclusion Higher estimated TLCPD as compared with higher IOP was better correlated with the presence and amount of glaucomatous optic nerve damage in patients with POAG. In contrast, higher IOP as compared to higher estimated TLCPD was better correlated with the prevalence of PACG. It supports the notion of an association of a low CSFP with the pathogenesis of POAG. (Ophthalmol CHN, 2016, 25: 225-231)

Key words: intraocular pressure, optic nerve, glaucoma, cerebrospinal fluid pressure, trans-lamina cribrosa pressure difference