One Surgery, Two Worlds: A Surgery-Level Carbon Footprint Analysis Of Phacoemulsification Between The Uk Nhs And Bangladesh

To perform the first surgery-level comparison of cataract carbon emissions between a UK NHS public system and a high-volume private eye hospital in Bangladesh, using two structurally distinct healthcare models to identify how system design, procurement policy, and surgical workflow influence environmental impact. This study aims to determine whether sustainable phacoemulsification is a transferable strategy that preserves safety, infection control, and patient satisfaction.

This prospective comparative study was conducted at two high-volume cataract centres with contrasting healthcare infrastructures. The UK arm included 500 standalone phacoemulsification procedures at Stoke Mandeville Hospital, NHS Trust. The Bangladesh arm included 500 standalone procedures at Bangladesh Eye Hospital (BEH), a private tertiary centre. Complex and combined cases were excluded to ensure comparability.

Surgical waste was recorded bin-by-bin using standardized segregation audits across all theatre zones. Energy consumption (HVAC, lighting, sterilization, and autoclave cycles) was extracted from estates and CSSD logs and normalized per case. Procurement-related emissions were calculated using lifecycle inventory data. Travel emissions were survey-based. Comparative lifecycle CO₂e was derived using EPA TRACI 2.1 methodology. Throughput-adjusted energy analysis was performed. Patient satisfaction and post-operative infection rates were prospectively assessed.

Each NHS phacoemulsification generates 128.3 kg CO₂e (primarily from disposable procurement) and 3.7 kg of solid waste. Averaging 12 cases/day, per-surgery energy use reaches 33.8 kWh (HVAC 30.4 kWh; autoclave 2.18 kWh) due to constant climate control and underfilled sterilisers. In contrast, Bangladesh Eye Hospital averages 37 cases/day, using just 8.4 kWh/case (HVAC 2.8 kWh; autoclave 0.093 kWh). BEH generates 17.1 kg CO₂e and 0.45 kg waste per case - reductions of 86% and 87.84% respectively, compared to the NHS. This is achieved through reusable tools, batch sterilization, and multi-use medications. No endophthalmitis occurred. Patient satisfaction was 95.1% in the UK and 90.9% in BEH.

After 500 procedures, the UK NHS generated 55.6 tCO₂e more than BEH, equivalent to 325,000 kilometres of driving. Despite an 86% lower carbon footprint and markedly reduced waste, BEH maintained comparable infection rates and high patient satisfaction, with no safety compromise observed. These findings demonstrate that surgical system design, including procurement models, instrument reusability, and throughput optimization, profoundly influences environmental impact. Low-carbon cataract surgery is achievable, scalable, and reproducible. As European ophthalmology advances sustainability frameworks, evidence-based adoption of resource-efficient practices can reduce emissions without compromising clinical excellence.