To the Editor:
Tetsumoto et al. [1] describe that the surgical results of air tamponade were not inferior to SF6 tamponade in 27 gauge Pars Plana Vitrectomy (PPV) for rhegmatogenous retinal detachments (RRD) in their study. A further consideration in the use of fluorinated gases during retinal surgery should be the environmental impact of these gases.
Fluorinated gases such as SF6 are controlled by the European Union with the aim of reducing their use by two-thirds by 2030 (compared to 2014) due to their greenhouse effect [2] (SF6 is the most potent greenhouse gas regulated by the Kyoto protocol [3] with a Global warming potential of 22,800 relative to CO2 [4]).
The fluorinated gas used in vitreoretinal (VR) surgery is either released into the atmosphere during gas exchange, expelled from the body via the bloodstream and respiration or remains within the canisters which are disposed of as medical waste. It would not be unreasonable to expect that all the remaining fluorinated gas in the canister is eventually released into the atmosphere.
In our tertiary regional referral centre for VR surgery a total of 18 single use canisters (30 ml) of SF6 and 34 canisters (30 ml) of C2F6 were used during the month of September 2019 (across all VR procedures). Using figures provided by the manufacturer Arcadophta (Toulouse, France) and an online calculator (United States Environmental Protection Agency [5]) this would equate to 6.48 L (62.6616 g) of SF6 and 12.24 L (106.1208 g) of C2F6 for our unit in 1 year. This is equivalent to a total of 2.7 metric tons of CO2 emissions per year in our one unit.
Whilst this is only a small contribution to the total environmental impact of the health sector, we should be aware of the global warming potential of these gases and ensure we minimise their use. If there is evidence that air tamponade is not inferior to fluorinated gas tamponade for some RRDs then the environmental considerations should be act as an impetus for further research.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Footnotes
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Tetsumoto A, Imai H, Hayashida M, Otsuka K, Mataumiya W, Miki A, et al. The comparison of the surgical outcome of 27-gauge pars plana vitrectomy for primary rhegmatogenous retinal detachment between air and SF6 gas tamponade. Eye. 2020;34:299–306. doi: 10.1038/s41433-019-0726-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.European Commission ec.europa.eu. 2020. https://ec.europa.eu/clima/policies/f-gas_en.
- 3.Rigby M, Muhle J, Miller BR, Prinn RG, Krummel PB, Steele LP, et al. History of atmospheric SF6 from 1973 to 2008. Chem Phys. 2010;10:10305–20. [Google Scholar]
- 4.United Kingdom Government gov.uk. 2020. https://www.gov.uk/guidance/calculate-the-carbon-dioxide-equivalent-quantity-of-an-f-gas.
- 5.United States Environmental protection Agency epa.gov. 2020. https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator.