Province to continue allowing macular degeneration injections despite glaucoma fears

The government of B.C. says injecting a drug into people's eyes to stave off blindness is safe and will continue despite the need for glaucoma surgery in some patients.

A long and detailed news release from the Ministry of Health on Friday follows a Globe and Mail article that says some eye doctors and surgeons in the province want the injections to stop.

In 2009, the province set up a retinal diseases treatment program to provide care for wet age-related macular degeneration (wet AMD), a leading cause of blindness in the elderly.

It's since treated 20,000 people in the province and uses the injections of anti-vascular endothelial growth factor (anti-VEGF) drugs for patients facing severe vision loss.

Affordable Avastin

The drugs used in the program aren't cheap. They cost the province $11.5 million in 2018-2019. One of them, Avastin, is significantly cheaper than the others and is used in the majority of cases to ensure affordability.

Avastin is an anti-cancer drug not approved by Health Canada to treat retinal disease but is used because of its success in treating wet AMD.

The province says there is concern that the treatment is related to potentially increased rates of patients needing glaucoma surgery following the injections.

Glaucoma is progressive damage to the optic nerve, which is usually related to elevated pressure in the eye. It leads to the progressive loss of vision.  

The province says the rate of increased glaucoma surgeries following the injections may be up to 2.1 per cent over two years of anti-VEGF therapy.

'Element of risk'

"All surgeries and medical interventions contain an element of risk," said Adrian Dix in the news release.

He says a team of 29 retinal specialists in the provincial program, along with two glaucoma specialists, have all said that while there is a level of risk associated with the treatments, suspending them will do more harm than good.

"The resulting lack of provision of these injections would pose a serious risk of further deterioration of vision and possible vision loss in patients," he said.

The province says work by the B.C. Centre for Disease Control and the Public Health Agency of Canada is underway to review data from the program and available research to look for any risks or trends it has not been able to uncover.

2nd review

The new review is welcomed by Dr. Derek Godinho who is president of the Association of British Columbia Retinal Specialists.

"We look forward to collaborating closely with government and our colleagues and are committed through this world-class program to ensuring safety and efficacy and continuing to preserve the vision of the many thousands of British Columbians with sight-threatening diseases," he said as part of the provincial statement.

The Provincial Health Services Authority, which runs the provincial program, says concerns about glaucoma rates were brought to its attention in late 2017. It conducted a quality review in 2018 but says that did not fully corroborate an overall increased rate of glaucoma surgery.

Data from the review found that glaucoma surgery in patients treated in the program appears relatively low overall.

The review also found no clear relationship between glaucoma surgical rates and the drug treatments used in the program or how they were prepared or administered.