Prospective Clinical Study of Non-Invasive Intracranial Pressure Measurements in Open-Angle Glaucoma Patients and Healthy Subjects

Abstract

Background and Objective: Glaucoma is a progressive optic neuropathy in which the optic nerve is damaged. The optic nerve is exposed not only to intraocular pressure (IOP) in the eye, but also to intracranial pressure (ICP), as it is surrounded by cerebrospinal fluid in the subarachnoid space. Here, we analyse ICP differences between patients with glaucoma and healthy subjects (HSs). Materials and Methods: Ninety-five patients with normal-tension glaucoma (NTG), 60 patients with high-tension glaucoma (HTG), and 62 HSs were included in the prospective clinical study, and ICP was measured non-invasively by two-depth transcranial Doppler (TCD). Results: The mean ICP of NTG patients (9.42 ± 2.83 mmHg) was significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p = 0.007). The mean ICP of HTG patients (8.11 ± 2.68 mmHg) was significantly lower than that of NTG patients (9.42 ± 2.83 mmHg) (p = 0.008) and significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p < 0.001). Conclusions: An abnormal ICP value could be one of the many influential factors in the optic nerve degeneration of NTG patients and should be considered as such instead of just being regarded as a “low ICP”.

Is Glaucoma a Two-Pressure-Related Optic Neuropathy? A Systematic Review and Meta-Analysis

“…In our study, the NTG group had a higher mean IOP than healthy controls (p<0.00001), which was similar to a recent study of Deimantavicius et al 26 This could be because the studies by Ren et al 5 and Lee et al 9 included NTG patients whose IOP was higher on average than in other studies in this systematic review.…”

“…Boye et al 29 measured the flow-range ratio between the intracranial cavity and SAS of the optic nerve in MRI diffusion images and demonstrated that this ratio was significantly lower in NTG compared to healthy people, indicating abnormal CSFp in NTG. In the study by Deimantavicius et al 26 , CSFp determined by two-depth transcranial Doppler (TCD) ultrasonography was lower in both the HTG and NTG groups than in healthy participants.…”

Human ophthalmic artery as a sensor for non-invasive intracranial pressure monitoring: numerical modeling and in vivo pilot study

“…It affected 76 million people in 2020 and is predicted to reach 111.8 million cases by 2040 5 . Prospective and retrospective studies using lumbar puncture technique have revealed that glaucoma patients have lower ICP than age-matched healthy subjects 6 – 9 , which suggests that ICP might be one of the influential factors in the pathophysiology of glaucoma 10 . However, ICP monitoring is not employed in daily practice for glaucoma patients due to its invasiveness.…”

“…A key problem in glaucoma diagnosis and treatment is minimizing the deformation of the lamina cribrosa caused by the pressure difference between the intraocular pressure (IOP) and ICP (IOP-ICP) 17 . Our previous studies showed that our non-invasive ICP snapshot measurement method is accurate and precise enough to be applied for abnormally low ICP value diagnosis in normal-tension glaucoma (NTH) and high-tension glaucoma (HTG) patients 10 , 18 .…”

Cerebrospinal fluid and ophthalmic disease

“…Despite the large body of evidence supporting a relationship between CSF pressure and glaucoma, it is worth noting that not all studies are seamlessly supportive. Deimantavicius et al [30 ▪ ] used transcranial Doppler to measure CSF pressure and found that patients with NTG had lower CSF pressure than healthy patients. However, these authors also found that patients with high tension glaucoma had lower CSF pressure than both NTG and healthy patients.…”