Carbon Footprint Reduction With A One-Visit See-And-Treat Immediate Sequential Bilateral Cataract Surgery Pathway: Cradle-To-Grave Life Cycle Assessment Within A Public Healthcare Model

To quantify greenhouse gas (GHG) emissions associated with a novel combined see-and-treat (S&T) immediately sequential bilateral cataract surgery (ISBCS) pathway using a cradle-to-grave life cycle assessment (LCA), and compare emissions with S&T delayed sequential bilateral cataract surgery (DSBCS) and a traditional DSBCS (TDSBCS) pathway. The study particularly aimed to determine whether combining S&T ISBCS produces meaningful carbon savings in routine NHS cataract care.

Royal Devon University Healthcare NHS Foundation Trust, South West England. The S&T pathways were delivered at NHS Nightingale Hospital Exeter and the traditional pathway at Axminster Hospital. Patients undergoing cataract surgery between 1 April and 31 July 2025 were eligible for inclusion.

Quality improvement service evaluation using observational clinical data. A process-based cradle-to-grave LCA aligned with ISO 14040/44 estimated 100-year global warming potential (kgCO2e). Functional unit: completion of bilateral cataract surgery for one patient from first pre-operative attendance(s) to discharge and home travel. Three arms (n=20 each): S&T+ISBCS (single visit), S&T+DSBCS (two visits), and traditional DSBCS (three visits). Inventory included surgical consumables, medicines, PPE, theatre/clinic energy, patient and staff travel, laundry/sterilisation and waste. Bootstrapped confidence intervals and sensitivity analyses were performed.

Sixty patients were analysed (mean age 78.4, 73.8, and 79.9 years for S&T ISBCS, S&TDSBCS, and TDSBCS respectively). Median (IQR) emissions per bilateral functional unit were 77.18 (6.29) kgCO2e for S&T ISBCS, 102.34 (3.83) kgCO2e for S&T DSBCS, and 125.33 (4.18) kgCO2e for TDSBCS. The principal difference between pathways was travel burden: S&T ISBCS required one attendance compared with two and three attendances respectively. Consequently, travel emissions rose progressively across pathways and were a major driver of overall footprint differences. S&T ISBCS reduced emissions by ~25 kgCO2e versus S&T+DSBCS and ~48 kgCO2e versus TDSBCS. Manufacturing and energy remained major contributors across all pathways

A single-visit S&T ISBCS cataract pathway substantially lowers carbon emissions compared with staged bilateral surgery models. The dominant mechanism is elimination of repeat hospital journeys, generating large travel-related carbon savings at patient and staff level, supported by reduced time in energy-intensive clinical environments. Because cataract surgery is performed at high volume, adoption of this pathway for suitable patients could deliver considerable system-wide environmental benefit whilst upholding clinical effectiveness. Further reductions will require addressing manufacturing emissions alongside pathway redesign.