At the Sustainability Expert Panel held at the American Society of Retina Specialists 2024 Annual Meeting, 3 speakers and 2 expert panelists from EURETINA discussed the environmental impact of retinal procedures and travel to retina professional meetings, and put forth ways that retina specialists can contribute to sustainability.
Environmental Impact of Intravitreal Injection Procedures
Dr. Jacob Grodsky opened by providing data from a comprehensive literature review that focused on sustainability and waste related to intravitreal injections (IVIs). Eight articles were identified, all of which were published since 2021.
Studies have estimated that each IVI generates an estimated 14 kg of CO2 emissions. This would translate into an estimated 210 million kg of CO2 emissions in the United States (US) annually. The primary contributors to this carbon footprint are patient transport (77%), procurement, and shipping. Each IVI also produces 190 g of medical waste, leading to a total annual estimated 2.85 million kg of landfill waste in the US.
Dr. Grodsky said that “this review really emphasizes the importance of this topic, as well as the extensive opportunity that we have as retinal specialists for impactful change, just given the sheer number of injections we perform, which is a number that will be likely to continue to increase with the aging population and new therapeutic advancements.” He and his team advocate for the development of durable treatments and sustained-release devices, as well as gene therapy advances to reduce the need for frequent patient visits.
“The most important take-home message you can take from this talk is really the importance of reflecting on your own practices, recognizing that each decision regarding the use of gloves, masks, drapes, etc., is compounded by the number of injections that you perform,” Dr. Grodsky concluded.
Post-Injection Endophthalmitis With the Use vs Non-Use of Gloves
The next speaker was Dr. David Anderson, whose team conducted a retrospective review of the practices of 19 retina specialists in a single practice over 2023. The specialists were surveyed on their injection practices: nitrile glove vs no glove use; speculum use; masking; injection quadrant; and method of local anesthesia. A sample cohort of 5 doctors was timed on how long it took them to don gloves.
Over the course of the year, 120,373 IVIs were performed and 20 cases of infectious endophthalmitis were noted, for a total endophthalmitis rate of 0.017%. Rates with no glove use vs glove use were 0.021% and 0.012%, which were statistically similar.
Based on the timings of the 5 physicians, the time spent donning gloves in the whole practice was estimated to be 290 hours of physician time annually. The estimated carbon footprint for glove use in the practice was 2000 tons of CO2 annually, the equivalent of running a gasoline car engine continuously for 5 years.
The Carbon Footprint of the 2013–2017 ASRS Annual Meetings
Air travel has been discussed as a large contributor to carbon emissions. Dr. Scott McClintic developed a localization optimization algorithm to identify a worldwide meeting location for ASRS that would minimize emissions for each meeting. The years 2013–2017 were chosen for inclusion in the algorithm because one meeting took place outside North America during that time (Vienna, Austria). Each attendee’s travel emissions were calculated by determining the geodesic distance between their business address and the convention center; assumptions were made about which attendees flew and which drove.
Vienna had the lowest attendance but the highest emissions. It was also the only meeting where American attendees were responsible for a higher proportion of emissions than their representation at the meeting (59% of emissions vs 51% of attendees).
Per capita emissions for the ASRS Annual Meeting are among the highest reported in the literature for medical conferences. The optimization algorithm found that a site in the US Northeast or Midwest would be ideal, and estimated that changing the location, assuming the same general attendance as past meetings, could reduce emissions by as much as 29%.
Panel Discussion
The 3 speakers were joined by the 2 experts Drs. Jens Kiilgaard and Martin Zinkernagel from EURETINA. They were asked what sustainability measures are being undertaken by retina specialists in Europe.
Dr. Kiilgaard said that Europe is discussing the same issues the US presenters brought up. Reducing travel wasn’t found to be feasible, and reducing garbage is proving to be difficult, since it is felt that not using gloves, drapes, etc., will have an impact on patient safety. It is important to go into discussion with industry to see significant reductions in packaging, but industry may claim that they have to stay within regulations, so talking with politicians is also important.
Dr. Zinkernagel concurred that sustainability needs to be a team effort encompassing physicians, patients, and industry. In Europe, the use of gas tamponade has become an issue; because the EU chemical agency is looking at banning the gases used in tamponade, exemptions will have to be made so that tamponade can continued to be performed. However, retina surgeons can jump-start the process by trying to reduce SF6 emissions in the operating room (e.g., off-gassing less of the SF6).
Dr. Kiilgaard noted that all efforts should be made to increase awareness about waste and sustainability measures. Discussions are difficult but needed, as “the next generation will feel the impact of what we are doing now,” he said.