Greener Cataract Surgery: Less Waste, Lower Costs

Cataract surgery is a high-yield opportunity for reducing the carbon footprint, with waste-reduction measures sustainable for both the environment and cost, according to Jonathan Malcolm MD.

Climate change is described as the greatest global health threat facing the 21st century. Surprisingly, studies demonstrated the health sector is responsible for 4.4% of global greenhouse gas emissions, compared to 2.5% from the aviation sector.^1–2

Notably, cataract surgery has a particularly high carbon footprint activity due to the high volumes of patients, especially in higher-income countries.

“It is estimated that the carbon footprint of a cataract surgery in the UK is 20 times greater than that around the Aravind Eye Hospital in India,” Dr Malcolm stated.³

The high carbon footprint in cataract surgery, particularly in high-income countries, is due to the preference of single-use items over reusables, as well as additional equipment and materials, which also have a significant economic impact. For instance, a 2019 US study showed the country spent more than $190,000 annually on unused pharmaceuticals per site.⁴

In a comparative study, Dr Malcolm analysed the cost and carbon footprint of topical and sub-Tenon’s anaesthesia for cataract surgery in the UK’s National Health Service by conducting a life cycle analysis of products, including waste disposal. It showed that sub-Tenon’s anaesthesia produced 0.5 kg more CO₂ equivalent per case when compared to topical anaesthesia, with a cost of more than £10 per case. Waste disposal accounted for only 1–4% of the carbon footprint due to proximity, with medical equipment and pharmaceuticals contributing more significantly.⁵ As Dr Malcolm pointed out, waste disposal is a small proportion of the overall carbon footprint of cataract surgery, as a Malaysian study also demonstrated by estimating that waste segregation and recycling could reduce the carbon footprint by only 0.139 kg CO₂ per surgery.⁶

The first step for reimagining ophthalmology in a sustainable way should be within departments, hospitals, and clinics, engaging all the staff working in the good cause. One method could be the Delphi process, as Dr Malcolm explained, noting it could help involve the staff in waste reduction efforts and to create an action plan. The Delphi process is a systematic methodology for achieving consensus of opinion through five multistage, anonymised steps: sending an email to gather ideas from the staff, collating anonymised lists, discussing with team members, ranking the ideas collected anonymously, and forming an action plan.

Describing his experience in Leeds in 2021–2022 with the Delphi process, Dr Malcolm underlined the staff’s unexpectedly strong engagement with sustainability. An email was sent to everyone—not only physicians, but the administration staff, nurses, optometrists, and healthcare residents. This generated 24 discrete ideas to reduce waste, which involved the removal of infrequently used items from standard cataract packs and optimising and designing those tools into more sustainable and streamlined packs labelled ‘eco-packs.’

Cataract surgery is common and resource intensive, with many challenges for the future, but nothing is really lost. “Waste reduction is the key and not only saves carbon, but it’s good for the pocket,” Dr Malcolm concluded.

Dr Malcolm presented at the 2025 ESCRS Annual Congress in Copenhagen.

Jonathan Malcolm MD is an ophthalmologist at Leeds Teaching Hospitals NHS Trust, Leeds, UK. jonathan.malcolm@nhs.net

1. Healthcare without harm, 2019, https://global.noharm.org/sites/default/files/documents-files/5961/HealthCaresClimateFootprint_092319.pdf

2. Ritchie H. Our World in Data, 8 Apr 2024, https://ourworldindata.org/global-aviation-emissions

3. Thiel CL, et al. J Cataract Refract Surg, 2017 Nov; 43(11): 1391–1398. doi:10.1016/j.jcrs.2017.08.017. PMID: 29223227; PMCID: PMC5728421.

4. Tauber J, et al. JAMA Ophthalmol, 2019; 137(10): 1156–1163. doi:10.1001/jamaophthalmol.2019.2901

5. Malcolm J, et al. Eye, 2024; 38: 1349–1354. doi:10.1038/ s41433-023-02902-4

6. Khor HG, et al. J Cataract Refract Surg, 2020; 46(2): 215–221. doi:10.1097/j.jcrs.0000000000000009