Here's How to Have 'Greener' Intravitreal Injections

STOCKHOLM — Simple changes, like minimizing patient visits and reducing the use of nonsterile gloves, can make a big difference in the environmental impact of intravitreal injections without compromising patient care, said experts speaking here at the American Society of Retina Specialists (ASRS) 2024 Annual Meeting.

Intravitreal injections have become standard procedures in retinal care to deliver medication directly into the vitreous humor for conditions like diabetic retinopathy, neovascular age-related macular degeneration, and choroidal neovascularization, with millions administered annually worldwide.

But a literature review has shed light on their environmental impact, revealing an enormous footprint.

Presenting the review findings, Jacob Grodsky, MD, of Ochsner Health in Louisiana, said that 15 million injections are conducted annually in the United States alone, generating a total annual estimate of the equivalent of 210 million kilograms of carbon dioxide emissions. Patient transport accounts for 77% of this carbon footprint, followed by procurement and shipping.

Each injection, he said, produces 190 g of medical waste, which equates to about 3 million kilograms of landfill waste in the United States. "We know from studies that reusing these shipping materials can significantly reduce this carbon footprint and landfill waste," said Grodsky.

To conduct the review, the team searched for keywords like sustainability, carbon footprint, medical waste, emissions, landfill, disposal, retina, and intravitreal injections. There were almost 8000 results, but only eight papers, all published in 2021, specifically reported on sustainability and waste relating to intravitreal injections.

Jens Kiilgaard, MD, PhD, an ophthalmologist at Copenhagen University Hospital, Copenhagen, Denmark, who was not involved in the review, said during the following panel discussion that he found the number "depressing," emphasizing the need to increase awareness on the topic and conduct more studies.

"This review emphasizes the importance of this topic but also the extensive opportunity that we have as retina specialists for impactful change, given the sheer number of injections we perform, which is likely to continue to increase with the ageing population and therapeutic advancements," Grodsky said.

"So next time that you inject, I urge you all to make one conscious decision that will not have any impact on patient safety but will decrease the waste that you produce and that will be multiplied by the number of injections you perform."

So What Might Those Decisions Be?

One way would be to develop more durable treatments that minimize patient visits, like sustained release devices and gene therapies.

Another would be to reduce packaging.

But Kiilgaard told Medscape Medical News that this is challenging, as it requires a conversation with industry, which in turn is required to follow strict regulations. "This is a heavy task. But it is a conversation we have to have because it's important for us and it's important for our children," he said. "The next generation will feel the impact of what we are doing now."

Gloves or No Gloves?

Glove use also has a big impact on clinical practice carbon footprints.

David Anderson, MD, PharmD, from Retina Consultants of Minnesota, and colleagues calculated that nitrile glove use in their multicenter retina practice generates 1296 tons of carbon dioxide every year. "That is equivalent to a gasoline engine running in a car for 5 years," he said.

But aren't sterile gloves an important part of infection prevention?

Anderson presented the findings of a retrospective study he and his colleagues conducted to examine the effect of nonsterile glove use on postinjection endophthalmitis rates in their multicenter retina practice. They analyzed data from more than 120,000 intravitreal anti–vascular endothelial growth factor injections performed by 19 physicians in 2023. Of these physicians, seven did not use gloves.

The team found that the overall endophthalmitis rate was low at 0.0166%, equivalent to approximately 1 in 6000 injections. While the incidence was lower in the gloved group (0.0123% or 1 in 8130) than in the non-gloved group (0.0215% or 1 in 4633), this difference did not reach statistical significance (P = .21498).

This suggests that using nonsterile gloves may not substantially reduce the risk for postinjection endophthalmitis, said Anderson, presenting the study results at ASRS.

Following the presentations, a panel highlighted three important points:

1. Addressing sustainability in ophthalmology requires cooperation among physicians, patients, industry partners, supply chain, and regulatory institutions.
2. The carbon footprint and waste generated by common procedures like intravitreal injections are considerable, meaning that there is potential for impactful change.
3. Simple changes, such as reconsidering the use of nonsterile gloves, can reduce the environmental impact of clinical practice without compromising patient safety.

"It is a team effort that we have to perform," said Martin Zinkernagel, MD, PhD, an ophthalmologist at the University Hospital Bern, Bern, Switzerland. He said the discussion concerns not only clinicians but also everyone involved in clinical practice, from industry to regulators, to policymakers.

Jens Kiilgaard is an advisory board member at Aura biosciences.

Martin Zinkernagel has consulted for Roche, Bayer, Alcon, and EURETINA and is on the board of directors of Eyeye.