U of T research sheds new light on glaucoma, provides hope for patients

Christopher.Sorensen — Tue, 08 Jan 2019 17:15:07 +0000

Christopher.Sorensen Tue, 01/08/2019 - 12:15

Cutline

A nurse in France administers an anti-glaucoma agent to a patient (photo by BSIP/UIG via Getty Images)

Topic

Laboratory Medicine and Pathobiology

Research & Innovation

St. Michael's Hospital

��Ƶ researchers have shown that fluid which flushes out the eye’s optic nerve doesn’t flow properly in mice with glaucoma – one of the world’s leading causes of permanent blindness.

The researchers – Neeru Gupta (left) and Yeni Yucel, both professors in U of T's Faculty of Medicine, as well as student Emily Mathieu – were the first to find, recently, that cerebrospinal fluid from the brain penetrates the optic nerve, rather than simply surrounding it.

Now, the team has uncovered that in a glaucoma model, far less of this fluid enters the optic nerve than in mice without glaucoma. The findings were published in the December issue of the journal Investigative Ophthalmology & Visual Science.

“This casts an entirely new light on glaucoma,” said Gupta (left), who is also chief of glaucoma at U of T's Faculty of Medicine and a clinician-scientist at St. Michael’s Hospital.

“If fluid is not getting into a nerve and that fluid exchange – good things getting in, bad things getting out – is disrupted, maybe that's part of the reason the optic nerve is damaged in glaucoma.”

Glaucoma is often undetected in its onset and once a patient receives the diagnosis, progressive vision loss is inevitable. The disease causes gradual degeneration of the optic nerve. While treatments help to protect vision, currently, there is no cure.

This is a puzzle the U of T team members have dedicated their research to solving. Gupta and Yucel – both professors cross-appointed to U of T's department of ophthalmology and vision sciences and the department laboratory medicine and pathobiology – discovered nearly a decade ago that the eye has a lymphatic system, which clears fluid and waste out of tissues. The inability to clear fluid from the eye causes a buildup of pressure, and pressure is a major risk factor for glaucoma.

“There's much more to this disease than we would like to think,” Gupta says. “Right now, we are able to tackle pressure in the eye that's measureable. If we can drop it, we slow progression. It's not a cure.”

The current finding is the first step to a new body of research, according to Yucel (below).

“Now that we know there’s a problem, we need to drill down to understand the elements of it. It may even explain space flight-associated neuro-ocular syndrome,” he says, referring to optic nerve fluid shifts and vision impairment suffered by astronauts in space missions.

Next, the team will explore why the flow is disrupted and what impact this has on the optic nerve.

“I see many people who are slowly losing their sight from glaucoma,” says Gupta. “Despite many of our treatments, it’s sometimes not enough. This discovery potentially offers new hope. As long as we keep looking, there’s hope for a better future for our glaucoma patients.”

The team's research was supported by the Canada Foundation for Innovation, Canadian Institutes of Health Research, Glaucoma Research Society of Canada and the Natural Sciences and Engineering Research Council of Canada, among others.

Higher cigarette prices would save millions of people, especially poor smokers: U of T leads study

ullahnor — Thu, 12 Apr 2018 18:56:02 +0000

Higher cigarette prices would save millions of people, especially poor smokers: U of T leads study

ullahnor Thu, 04/12/2018 - 14:56

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Photo by Andrew Pons on Unsplash

Ana Gajic

Topic

Global Lens

Dalla Lana School of Public Health

Subheadline

Research finds taxing cigarettes could keep people out of poverty and save lives

Higher cigarette prices would save millions of people from extreme poverty and poor health around the world, while also cutting health treatment costs for families across the globe, suggests a new study.

The analysis, led by U of T Professor Prabhat Jha and the World Bank's Patricio V. Marquez, concludes that people with lower incomes would benefit the most from higher cigarette prices. Examining 500 million male smokers in 13 countries, they found that a 50 per cent increase in the tobacco excise tax would result in 67 million men quitting smoking, with the largest share being low-income men. It would also reduce years of life lost and decrease the risk of high medical costs.

The study was published this week in The BMJ. It adds to a growing body of knowledge that tobacco taxes, which are not implemented globally, have significant health benefits.

“Our study debunks the current narrative that higher cigarette prices would negatively impact the poorest among us,” said Dr. Jha (pictured at left), a professor of epidemiology at U of T's Dalla Lana School of Public Health.

“This analysis shows the opposite – a higher price would encourage cessation, lead to better health and save money, much more strongly for the poor than the rich.”

Small steps taken by governments can lead to unprecedented health gains and poverty reduction, he added.

Read about the research at Fortune

Read the Daily Telegraph story

The higher price would lead to 15.5 million men avoiding catastrophic health spending in the seven countries studied without universal health coverage, according to the study. This would result in 8.8 million men avoiding extreme poverty, half of whom are in the bottom income group.

Quitting smoking would result in 449 million years of life gained, the study showed. Higher tobacco costs would also benefit households globally, with about US$157-billion averted to treat the four main tobacco-attributable diseases examined: chronic obstructive pulmonary disease, stroke, heart disease and cancer.

Despite more awareness of the risks, Jha said, if nothing changes, smoking will be responsible for one billion deaths in the 21st century. Most of these will be in low- and middle-income countries. Previous research by Jha, who is also director of the Centre for Global Health Research of St. Michael’s Hospital, has shown that raising taxes on tobacco is the single most effective intervention to lower smoking rates and to deter future smokers.

Building on his earlier research, Jha and the team undertook this new analysis to understand the true impact of higher cigarette prices around the world. They conducted an assessment across 13 middle-income countries with diverse socioeconomic characteristics, tobacco use and health-care coverage. Focusing on male smokers – who make up 90 per cent of smokers in the selected countries – the researchers used mathematical models to quantify the effect of a 50 per cent increase in prices.

“The findings of our new analysis will have a far-reaching impact,” said Marquez, the lead health specialist at the World Bank. “Not only does increasing tobacco taxation reduce smoking and its health consequences, but the study’s findings are also relevant to the United Nations sustainable development goals to reduce poverty and improve health.”

The study was supported by the Fogarty International Center of the U.S. National Institutes of Health, the Dalla Lana School of Public Health, Canadian Institute of Health Research, the Bill & Melinda Gates Foundation, Bloomberg Philanthropies, and the International Development Research Centre.