Correlation between Trans-lamina Cribrosa Pressure Difference and Morphologic Parameters of Optic Disc in Normal Tension Glaucoma Patients

PURPOSE: To investigate the relationship between trans-lamina cribrosa pressure difference (TLCPD) and morphologic parameters of optic disc (OD) in normal tension glaucoma (NTG) patients. METHODS: Data from 31 NTG patients (31 eyes) and 29 controls (29 eyes) were analyzed retrospectively. Their cerebrospinal fluid pressure was estimated using diastolic pressure (DBP), body mass index (BMI) and age. TLCPD was defined as the difference of intraocular pressure (IOP) and the estimated cerebrospinal fluid pressure (ECSFP). Measurements of the rim area (RA), disc area (DA), average and vertical cup/disc (C/D) ratio, retinal nerve fiber layer thickness (RNFLT) and cup volume (CV) were taken for all patients using optical coherence tomography. The correlation between TLCPD and morphologic parameters of OD were assessed. RESULTS: There were no significant differences between the two groups in terms of age, DBP, IOP and spherical equivalent (SE) and BMI. The mean ECSFP was significantly higher in the controls (10.7 ± 2.8 vs. 12.2 ± 2.2 mm Hg, p = 0.031) and TLCPD was significantly higher in patients (2.4 ± 2.1 vs. 4.9 ± 3.7 mm Hg, p = 0.002). In the NTG group, there was a negative correlation between TLCPD and RA (r = -0.595) and positive correlations between TLCPD and the average C/D ratio (r = 0.504), vertical C/D ratio (r = 0.434) and CV (r = 0.420). Average RNLFT was also significantly correlated with TLCPD (r = -0.500) and RNFLT for four quadrants, except the nasal quadrant, in NTG patients. CONCLUSIONS: NTG patients had higher TLCPD. A higher TLCPD was associated with a narrower RA, larger C/D ratio, and thinner RNFLT.

Cerebrospinal Fluid Pressure and Trans-lamina Cribrosa Pressure Difference in Open-angle Glaucoma: KNHANES V

PURPOSE: To investigate the relationships between estimated cerebrospinal fluid pressure (CSFP) and trans-lamina cribrosa pressure difference (TLCPD) in open-angle glaucoma (OAG) in Korean population. METHODS: A total of 10,801 eyes were included from the Korean National Health and Nutrition Examination Survey V. All participants (aged 19 years or older) were classified as non-glaucomatous group, OAG suspect group and OAG group. CSFP was calculated as CSFP (mm Hg) = 0.44 body mass index (kg/m²) + 0.16 diastolic blood pressure (mm Hg) - 0.18 age (years) - 1.91. TLCPD was calculated by subtracting CSFP from intraocular pressure. RESULTS: The mean estimated CSFP was (8.7 ± 3.3 mm Hg vs. 11.6 ± 3.7 mm Hg, 11.2 ± 3.8 mm Hg vs. 11.6 ± 3.7 mm Hg) was lower, and the mean TLCPD (5.7 ± 4.4 mm Hg vs. 2.2 ± 4.4 mm Hg, 3 ± 4.7 mm Hg vs. 2.2 ± 4.4 mm Hg) was higher in the OAG group and in the OAG suspect group than in the non-glaucomatous control group, respectively (p < 0.001). After adjusting relating factor with CSFP and TLCPD using simple linear regression and multivariate analyses, the mean estimated CSFP was distributed lower (p < 0.001; beta: -0.12; B: -2.306; 95% confidence interval [CI]: -2.717, -1.895) in OAG group than in non-glaucomatous group and the mean TLCPD was distributed higher (p < 0.001; beta: 0.099; B: 1.349; 95% CI: 0.977, 1.72; p < 0.001; beta: 0.118; B: 2.776; 95% CI: 2.264, 3.289) in OAG suspect group and in OAG group than in non-glaucomatous group, respectively. CONCLUSIONS: Estimated CSFP and calculated TLCPD showed essential association with OAG presence. It supports the potential role of low CSFP in the pathogenesis of OAG.