A group of scientists from Lithuania and other countries have found more proof that pressure inside the head can affect a certain type of glaucoma called normal tension glaucoma. This type of glaucoma is responsible for up to half of all glaucoma cases.
A recent study showed that people with lower pressure inside their head had worse vision, especially in the part of the eye that is close to the nose. Glaucoma is a common eye disease that can cause blindness in older people. It happens when the nerve that helps us see gets damaged.
Usually, glaucoma is linked to high pressure inside the eye, but sometimes it happens even when the pressure is normal. This is called normal tension glaucoma, and it affects anywhere from 30 to 90 percent of people with glaucoma.
Glaucoma can cause blindness and is caused by damage to the optic nerve. It is often linked to high pressure inside the eye, but not always. In cases of normal tension glaucoma, eye pressure is normal, yet the disease still develops. Scientists are discovering that glaucoma may actually be caused by two pressures: one inside the eye and one inside the skull.
The optic nerve is connected to the brain and surrounded by fluid, so both pressures can affect it. Researchers are studying the balance between these pressures and its connection to glaucoma development. A professor from Lithuania created a non-invasive way to measure the pressure inside the skull and found that low pressure is linked to poor vision in certain areas of the eye.
Researchers from Lithuanian, Israeli, and American universities recently conducted a study on 80 patients with early-stage normal tension glaucoma (NTG). The study included measurements of intraocular pressure (IOP), intracranial pressure (ICP), and visual field perimetry. The results showed that there were correlations between intracranial pressure, translaminar pressure difference (TPD), and visual field changes. TPD is calculated by subtracting ICP from IOP, and a higher TPD was linked to more significant visual field damages, especially in the nasal zone.
The study suggests that a lower intracranial pressure could be a risk factor for normal-tension glaucoma. Visual field loss is a sign of blindness, so it’s crucial to understand the causes of this condition and find ways to reverse it.
Professor Ragauskas and his team at Kaunas University of Technology have been researching the relationship between brain pressure and glaucoma for several years. They have developed a non-invasive technology that measures intracranial pressure, which is the pressure inside the skull, through the eye using ultrasound. In a recent study, they found that there is a correlation between low brain pressure and visual field loss in patients with normal tension glaucoma.
Their invention, called the two-depth Transcranial Doppler, has been patented in the US and Europe for various industrial applications. Although they are currently using it for research purposes in ophthalmology, they are constantly developing it and exploring other areas where measuring brain pressure is important, such as in long-term space missions.