Dr John Buchan, Assistant Professor of International Eye Health LSHTM
Climate change is regarded by many as the greatest long-term threat to global health in the 21st century. Although modest progress has been made by many sectors, overall, global greenhouse gas (GHG) emissions continue to rise.
Health services are substantial contributors to national greenhouse gas emissions in many countries, representing 10% of the total national GHG emission in the USA, 7% in Australia, 5% in Canada and Japan, and 4% in the UK. A 2019 report estimated that health care emissions contributed up to 5% of all global greenhouse gas emissions (excluding African countries).
Eye care contributes a substantial part of these emissions. For example, in the UK, ophthalmology is the highest volume speciality, accounting for 8.1% of hospital outpatient visits nationally in 2018–19.
The adverse effects of eye care delivery on the environment will probably increase. Ongoing innovation is broadening the range of interventions available, and demand is increasing as the world population grows and ages.
Consequently, the environmental impact of eye health services will continue to increase unless substantial changes are made to current practice.
As part of the Lancet Global Health Commission on Global Eye Health, the International Centre for Eye Health led a study to establish the nature and extent of the literature describing the environmental costs of delivering eye care services, interventions to diminish these impacts, and to identify key sustainability themes that are not currently being addressed.
The main finding was the vastly unequal environmental cost of delivering clinical services in different regulatory settings, despite similar clinical outcomes. For example, a phacoemulsification cataract extraction in a UK hospital produced more than 20 times the greenhouse gas emission of the same procedure in an Indian hospital. Both surgeries however have excellent outcomes for patients, implying that clinical practice in high-income countries, largely dictated by regulations and guidelines, is unnecessarily wasteful without demonstrable improvements in patient safety.
It is extremely hard to quantify the health risk to individuals due to specific environmental activities, but this may often outweigh a small gain in patient safety or quality of life due to an unsustainable practice. New interventions have to demonstrate cost-effectiveness before being adopted, however practices that are introduced to theoretically promote safety do not have to show cost utility, even when the benefits are dwarfed by financial or environmental cost. For instance, there is currently nowhere globally that considers what mass of CO2 emission per quality adjusted life-year is acceptable.
Since some low-income countries are already performing more environmentally economical procedures with little difference in safety, real-world evidence needs to be generated in lower income countries that can be applied in higher income settings.
Several of the UN Sustainable Development Goals (SDGs) intersect with the way we deliver health care, including: SDG3 on Good Health and Wellbeing, SDG12 on Responsible Consumption and Production, and SDG13 on Climate Action. WHO published guidance on increasing the environmental sustainability of health-care facilities in October 2020, but the guidance, although welcome, was not able to cite any peer-reviewed evidence from trials of proposed interventions to promote environmental sustainability.
Similarly, a 2021 scoping review reporting interventions to improve the quality of cataract surgery, proposed the addition of planetary health to the seven dimensions of quality accepted by WHO, but was unable to identify any study targeting this aspect of quality in cataract service delivery.
By generating robust evidence to assess the impact of eye care services on the environment and setting relevant goals to reduce it we can improve our field’s impact on the world without compromising patient safety. This will in turn lead to the inclusion of environmental impact when developing health policies.
The buying power of a large speciality such as ophthalmology gives it the opportunity to have an impact across health care, encouraging sustainable manufacturing, packaging, and energy supplies. With sufficient research and planning, the eye care sector will be able to contribute to the improvement of our planet.
Buchan C, Thiel CL, Steyn A, Somner J, Venkatesh R, Burton MJ, Ramke J. Addressing the environmental sustainability of eye health-care delivery: a scoping review. Lancet Planetary Health. June 2022. https://doi.org/10.1016/S2542-5196(22)00074-2