Tag: optic nerve

Categories : OphthalmologyTags :

Many Old People may be Unaware that They Have Glaucoma

On By ModernMedia
Photo by Mari Lezhava on Unsplash

Research on 70-year-olds carried out at the University of Gothenburg, found that nearly 5% had glaucoma – with half of whom were unaware that they had the disease. The study also confirmed hereditary factors were involved in the disease and that intraocular pressure was normal in two-thirds of those newly diagnosed.

Glaucoma is a common eye disease that damages the optic nerve and thereby the field of vision and can lead to blindness. One of the most common risk factors for it is raised intraocular pressure, exceeding the normal range of 11–21mmHg.

The research, published in Acta Ophthalmologica, was carried out by Lena Havstam Johansson, a PhD student at the University of Gothenburg and a specialist nurse at Sahlgrenska University Hospital. The study shows that 4.8% of the 560 study participants examined by eye specialists had glaucoma.

“Of those who were diagnosed with glaucoma via the study, 15 people – or 2.7% of all participants – were unaware that they had the disease before being examined,” says Lena Havstam Johansson. “So half of those who turned out to have glaucoma were diagnosed because they took part in the study.”

For those who were newly diagnosed, the discovery of the disease meant they could start treatment with daily eye drops to reduce intraocular pressure, slowing the progression of optic nerve damage.

Glaucoma impacts some areas of life – but not others

People with glaucoma had similar levels of physical activity to those without the disease and did not smoke more, or drink more alcohol. They rated their overall quality of life as being just as good as others, they were not more tired or more depressed.

“This was a positive surprise, and was a finding that I hope can bring comfort to many people who have been diagnosed with glaucoma. It’s hard to live with a disease that gradually impairs vision, but life can still be good in many ways.”

By contrast, people with glaucoma reported that their vision-related quality of life was poorer.

“It’s harder to climb stairs, see curbs in the evening, and notice things in your peripheral vision. This means that people with glaucoma may avoid visiting others, or going to restaurants or parties, and instead stay at home. They lose their independence, and may feel frustrated about it.”

Ongoing study of 70-year-olds

The research was carried out as part of the H70 study, examining the health of older people, which has been conducted at the University of Gothenburg for fifty years. The H70 study continuously invites all 70-year-olds born in a certain year in Gothenburg to attend several comprehensive physical and cognitive examinations. The 1203 70-year-olds included in the glaucoma study were born in 1944. For these studies, 1182 participants answered written questions about their eye health and the presence of glaucoma in their family. Eye specialists at Sahlgrenska University Hospital also examined 560 of the participants.

The findings confirm that there are hereditary factors behind the disease, as those diagnosed with glaucoma were more likely to have a close relative with the same diagnosis. The results also confirm that glaucoma involves higher intraocular pressure, although they also show that the majority of those who were newly diagnosed (67%) still had normal eye pressure.

During the early stages of the disease, the healthy eye can compensate for the loss of vision, meaning that many people believe their vision is as good as before. These studies confirm that glaucoma often does not initially involve a loss of visual acuity, which may make it harder to detect the disease.

Source: University of Gothenburg

Categories : NeurologyTags :

Eye Pressure in Glaucoma not the Whole Story

On By ModernMedia

The findings of a new study in rats show that a chemical known to protect nerve cells also slows glaucoma, the leading cause of irreversible blindness.

According to the National Glaucoma Foundation, in the US, over 3 million have glaucoma, with only half being aware of the fact and more than 120 000 are blind from the disease. The World Health Organization estimates that, worldwide, over 60 million individuals suffer from glaucoma.  

Led by researchers at NYU Grossman School of Medicine, the study centred on the watery fluid inside the eye on which its function depends. In patients with glaucoma, a buildup of fluid pressure wears down cells in the eyes and the nerves connecting them to the brain.

Previous research that despite eye pressure having been controlled, the condition progressively worsened. The relationship between pressure buildup and impaired vision remains poorly understood

The new study showed that when rats ingested the compound citicoline, optic nerve signals between the brain and eye were almost fully restored. Citicoline is a major source of choline, a building block in the membranes that line nerve cells and enhance nerve cell communication. It is produced in the brain but also commercially produced.

The study confirmed that increased eye pressure levels contributes to nerve damage in glaucoma, but  it also showed that citicoline reduced vision loss in rats without reducing pressure levels.

“Our study suggests that citicoline protects against glaucoma through a mechanism different from that of standard treatments that reduce fluid pressure,” said senior author Kevin Chan, PhD, an assistant professor in the Department of Ophthalmology at NYU Langone Health. “Since glaucoma interrupts the connection between the brain and eye, we hope to strengthen it with new types of therapies.”

The findings are helping scientists better understand how glaucoma works and add to past evidence that citicoline may counter the disease, said Chan, also the director of the Neuroimaging and Visual Science Laboratory at NYU Langone. It is known that humans and rodents with glaucoma have lower than normal levels of choline in the brain, but until now, Prof Chan says, there’s been little concrete evidence of the effectiveness of choline supplements as a therapy for glaucoma or why choline occurs in lower levels in glaucoma patients.

Prof Chan and his team tested whether increasing levels of that chemical would slow or even stop the degradation of the optic nerve and other regions of the brain involved in vision. Using a comprehensive study of the eye-brain connection in glaucoma, his team found that giving rats oral doses of citicoline over a three-week period protected nerve tissues and reduced vision loss sustainably even after the treatment stopped for another three weeks.

To simulate glaucoma, the researchers used a clear gel in rats to build up eye pressure mildly without otherwise blocking their vision. Then, the team used MRI imagery to measure the structural integrity and the amount of functional and physiological activity along the visual pathway. To test the clarity of vision of each eye, the researchers tracked the rodents’ visual behaviour .

It was found that for rats with mildly elevated eye pressure, the tissues that connect the eye and brain, including the optic nerve, degraded for up to five weeks after the injury. Nerve structure breakdown in the citicoline-treated rodents slowed by up to 74%, which the researchers said indicates that the chemical had protective effects on nerve cells.

However, more research is necessary before citicoline supplements to treat glaucoma in humans, as commercial drugs have yet to be proven fully effective in clinical trials. The researchers are planning next to look into how choline protects the eye and why it is depleted in glaucoma patients.

Source: Medical Xpress

Journal information: Yolandi van der Merwe et al, Citicoline Modulates Glaucomatous Neurodegeneration Through Intraocular Pressure-Independent Control, Neurotherapeutics (2021). DOI: 10.1007/s13311-021-01033-6