Trans-Lamina Cribrosa Pressure Difference and Open-Angle Glaucoma. The Central India Eye and Medical Study

Jost B Jonas,Diya Yang,Karishma Bhate,Xiaobin Xie,Vinay Nangia,Prabhat Nangia,Purna Nangia,Songhomitra Panda-Jonas,Ningli Wang,Yingfeng Zheng

doi:10.1371/journal.pone.0082284

Abstract

PurposeTo assess associations of the trans-lamina cribrosa pressure difference (TLCPD) with glaucomatous optic neuropathy.MethodsThe population-based Central India Eye and Medical Study included 4711 subjects. Based on a previous study with lumbar cerebrospinal fluid pressure (CSFP) measurements, CSFP was calculated as CSFP[mmHg] = 0.44 Body Mass Index[kg/m2]+0.16 Diastolic Blood Pressure[mmHg]−0.18×Age[Years] −1.91. TLCPD was IOP–CSFP.ResultsMean TLCPD was 3.64±4.25 mm Hg in the non-glaucomatous population and 9.65±8.17 mmHg in the glaucomatous group. In multivariate analysis, TLCPD was associated with older age (P<0.001; standardized coefficient beta:0.53; regression coefficient B:0.18; 95% confidence interval (CI):0.17, 0.18), lower body mass index (P<0.001; beta: −0.28; B: −0.36; 95%CI: −0.38, −0.31), lower diastolic blood pressure (P<0.001; beta: −0.31; B: −0.12; 95%CI: −0.13, −0.11), higher pulse (P<0.001; beta:0.05; B:0.02; 95%CI:0.01,0.2), lower body height (P = 0.02; beta: −0.02; B: −0.01; 95%CI: −0.02,0.00), higher educational level (P<0.001; beta:0.04; B:0.15; 95%CI:0.09,0.22), higher cholesterol blood concentrations (P<0.001; beta:0.04; B:0.01; 95%CI:0.01,0.01), longer axial length (P = 0.006; beta:0.03; B:0.14; 95%CI:0.04,0.24), thicker central cornea (P<0.001; beta:0.15; B:0.02; 95%CI:0.02,0.02), higher corneal refractive power (P<0.001; beta:0.07; B:0.18; 95%CI:0.13,0.23) and presence of glaucomatous optic neuropathy (P<0.001; beta:0.11; B:3.43; 95%CI:2.96,3.99). Differences between glaucomatous subjects and non-glaucomatous subjects in CSFP were more pronounced for open-angle glaucoma (OAG) than for angle-closure glaucoma (ACG) (3.0 mmHg versus 1.8 mmHg), while differences between glaucomatous subjects and non-glaucomatous subjects in IOP were higher for ACG than for OAG (8.5 mmHg versus 3.0 mmHg). Presence of OAG was significantly associated with TLCPD (P<0.001; OR:1.24; 95%CI:1.19,1.29) but not with IOP (P = 0.08; OR:0.96; 95%CI:0.91,1.00). Prevalence of ACG was significantly associated with IOP (P = 0.04; OR:1.19; 95%CI:1.01,1.40) but not with TLCPD (P = 0.92).ConclusionsIn OAG, but not in ACG, calculated TLCPD versus IOP showed a better association with glaucoma presence and amount of glaucomatous optic neuropathy. It supports the notion of a potential role of low CSFP in the pathogenesis of open-angle glaucoma.

Highlights

The trans-lamina cribrosa pressure difference (TLCPD) has been defined as the difference between intraocular pressure (IOP) minus cerebrospinal fluid pressure (CSFP), while the IOP, in a strict physical sense, is the transcorneal pressure difference between the intraocular compartment and the surrounding external atmosphere [1,2]
TLCPD was associated with older age (P,0.001; standardized coefficient beta:0.53; regression coefficient B:0.18; 95% confidence interval (CI):0.17, 0.18), lower body mass index (P,0.001; beta: 20.28; B: 20.36; 95%CI: 20.38, 20.31), lower diastolic blood pressure (P,0.001; beta: 20.31; B: 20.12; 95%CI: 20.13, 20.11), higher pulse (P,0.001; beta:0.05; B:0.02; 95%CI:0.01,0.2), lower body height (P = 0.02; beta: 20.02; B: 20.01; 95%CI: 20.02,0.00), higher educational level (P,0.001; beta:0.04; B:0.15; 95%CI:0.09,0.22), higher cholesterol blood concentrations (P,0.001; beta:0.04; B:0.01; 95%CI:0.01,0.01), longer axial length (P = 0.006; beta:0.03; B:0.14; 95%CI:0.04,0.24), thicker central cornea (P,0.001; beta:0.15; B:0.02; 95%CI:0.02,0.02), higher corneal refractive power (P,0.001; beta:0.07; B:0.18; 95%CI:0.13,0.23) and presence of glaucomatous optic neuropathy (P,0.001; beta:0.11; B:3.43; 95%CI:2.96,3.99)
Differences between glaucomatous subjects and non-glaucomatous subjects in CSFP were more pronounced for open-angle glaucoma (OAG) than for angle-closure glaucoma (ACG) (3.0 mmHg versus 1.8 mmHg), while differences between glaucomatous subjects and non-glaucomatous subjects in IOP were higher for angleclosure glaucoma (ACG) than for OAG (8.5 mmHg versus 3.0 mmHg)

Summary

Introduction

The trans-lamina cribrosa pressure difference (TLCPD) has been defined as the difference between intraocular pressure (IOP) minus cerebrospinal fluid pressure (CSFP), while the IOP, in a strict physical sense, is the transcorneal pressure difference between the intraocular compartment and the surrounding external atmosphere [1,2]. Since the lamina cribrosa of the optic nerve head, as the presumed site of glaucomatous damage to the optic nerve, is the pressure shed between the intraocular compartment and the retrolaminar compartment with the cerebrospinal fluid space, it has been discussed that the TLCPD as compared with the IOP may be more important for the pathophysiology of the optic nerve head including the development of glaucomatous optic neuropathy [3,4,5,6,7,8,9,10,11] To test this hypothesis, we examined whether TLCPD as compared with IOP is better correlated with the presence of glaucoma and with indices indicating the amount of glaucomatous optic nerve damage. Since measurement of CSFP as one part of the equation to calculate the TLCPD is invasive, we estimated the CSFP based on diastolic blood pressure, age and body mass index, using a formula which was derived in a previous investigation on the relationship between these three parameters [12]

Methods

Results

Discussion

Conclusion