Estimated Trans-Lamina Cribrosa Pressure Differences in Low-Teen and High-Teen Intraocular Pressure Normal Tension Glaucoma: The Korean National Health and Nutrition Examination Survey

Abstract

BackgroundTo investigate the association between estimated trans-lamina cribrosa pressure difference (TLCPD) and prevalence of normal tension glaucoma (NTG) with low-teen and high-teen intraocular pressure (IOP) using a population-based study design.MethodsA total of 12,743 adults (≥ 40 years of age) who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) from 2009 to 2012 were included. Using a previously developed formula, cerebrospinal fluid pressure (CSFP) in mmHg was estimated as 0.55 × body mass index (kg/m2) + 0.16 × diastolic blood pressure (mmHg)—0.18 × age (years)—1.91. TLCPD was calculated as IOP–CSFP. The NTG subjects were divided into two groups according to IOP level: low-teen NTG (IOP ≤ 15 mmHg) and high-teen NTG (15 mmHg < IOP ≤ 21 mmHg) groups. The association between TLCPD and the prevalence of NTG was assessed in the low- and high-teen IOP groups.ResultsIn the normal population (n = 12,069), the weighted mean estimated CSFP was 11.69 ± 0.04 mmHg and the weighted mean TLCPD 2.31 ± 0.06 mmHg. Significantly higher TLCPD (p < 0.001; 6.48 ± 0.27 mmHg) was found in the high-teen NTG compared with the normal group. On the other hand, there was no significant difference in TLCPD between normal and low-teen NTG subjects (p = 0.395; 2.31 ± 0.06 vs. 2.11 ± 0.24 mmHg). Multivariate logistic regression analysis revealed that TLCPD was significantly associated with the prevalence of NTG in the high-teen IOP group (p = 0.006; OR: 1.09; 95% CI: 1.02, 1.15), but not the low-teen IOP group (p = 0.636). Instead, the presence of hypertension was significantly associated with the prevalence of NTG in the low-teen IOP group (p < 0.001; OR: 1.65; 95% CI: 1.26, 2.16).ConclusionsTLCPD was significantly associated with the prevalence of NTG in high-teen IOP subjects, but not low-teen IOP subjects, in whom hypertension may be more closely associated. This study suggests that the underlying mechanisms may differ between low-teen and high-teen NTG patients.

Vascular and metabolic comorbidities in open‐angle glaucoma with low‐ and high‐teen intraocular pressure: a cross‐sectional study from South Korea

“…Using 2010–2012 KHANES data, we previously demonstrated that in the low‐teen IOP group, OAG was more significantly associated with hypertension and taking antihypertensive medication, while in the high‐teen IOP group, a higher estimated trans‐lamina cribrosa pressure difference was associated with OAG prevalence (Lee et al. ). The findings of this study were consistent with the results from prior studies, in which low‐teen OAG subjects were more likely to have vascular and metabolic comorbidities than were subjects with high‐teen OAG, and further add to the current hypothesis that vascular factors are more closely related to OAG with low‐teen baseline IOP.…”

Glaucoma: the retina and beyond

“…The authors caution, however, that further experimental investigations and longitudinal prospective clinical studies are required to overcome the methodological weaknesses of the current studies, concerns echoed by Pircher and Killer [138]. Since this time, the Beijing intracranial and intraocular pressure (iCOP) reported a positive association between TLPD (calculated from LP-CSFP) and visual field defects in POAG patients [77] and a population-based study from the Korean National Health and Nutrition Examination Survey (KNHANES) found that TLPD (calculated from estimated CSFP values) was significantly associated with HT-NTG [104]. …”

Intracranial and Intraocular Pressure at the Lamina Cribrosa: Gradient Effects

“…Although non-invasive methods would be preferable due to the risk of complications with the invasive ones, the indirect methods are not considered to be sufficiently reliable for clinical practice [ 37 – 40 ]. Still, conclusions on TLCPD are based on studies that used indirect methods to estimate TLCPD [ 70 , 71 , 73 , 74 , 76 ].…”

“…Similarly, Lee et al used the same mathematical formula to estimate ICP. They found an association between higher TLCPD and NTG with high-teen IOP values, but the same was not true for low-teen NTG patients [ 74 ].…”