Abstract
Purpose:
Recent experimental and clinical researches have suggested that orbital cerebrospinal fluid pressure (CSFP) may play a important role in the pathogenesis of glaucomatous optic neuropathy. We evaluated a potential association of normal tension glaucoma (NTG) with low CSFP or high trans-lamina cribrosa pressure difference (TLCPD) compared to high tension glaucoma (HTG) in a population-based setting, the Korean National Health and Nutrition Exam Survey (KNHANES).
Methods:
The population-based, cross-sectional survey (KNHANES, 2010-2012) included 8,729 individuals (267 subjects with NTG, 29 with HTG, 8,433 in the control) aged 40 years and older. All participants completed a comprehensive questionnaire and underwent ophthalmic examination including intraocular pressure (IOP) by Goldmann applanation tonometry as well as a systemic evaluation including, anthropometry and serologic test. Estimated CSFP was calculated from the reported formula used in the Beijing Eye Study 2011 [CSFP (mm Hg) = 0.44 x Body Mass Index (kg/m2) + 0.16 x Diastolic Blood Pressure (mmHg) - 0.18 x Age (years) - 1.91]. TLCPD was considered as IOP-CSFP. To identify the independent risk factors for NTG or open-angle glaucoma, multivariate logistic regression analysis was performed.
Results:
Mean IOP was 14.6 ± 3.0 mmHg in NTG, 20.7±11.5 mmHg in HTG and 13.9 ± 2.7 mmHg in the control group. In NTG group, CSFP was lower (9.8 vs. 10.5 mmHg) and TLCPD was higher (4.7 vs. 3.4 mmHg) than control group (P=0.004, P<0.001, respectively). However, CSFP did not show significant difference between HTG and control group (10.2 vs. 10.5 mmHg, P=0.66). Multinomial logistic regression demonstrated that higher IOP (OR=1.101, P<0.001), lower CSFP (OR=0.948, P=0.004) and higher TLCPD (OR=1.074, P<0.001) were risk factors for NTG. Higher IOP and TLCPD were also risk factors for HTG, however, lower CSFP did not show statistical significance (OR=0.975, P=0.64).
Conclusions:
Low CSFP and elevated TLCPD as well as elevated IOP were significant risk factors for normal tension glaucoma in this study. Thus, low CSFP besides elevated IOP may play a potential role in the pathogenesis of normal tension glaucoma.