Cataract surgery and environmental sustainability: Waste and lifecycle assessment of phacoemulsification at a private healthcare facility

Abstract

Purpose: To measure the waste generation and lifecycle environmental emissions from cataract surgery via phacoemulsification in a recognized resource-efficient setting.

Setting: Two tertiary care centers of the Aravind Eye Care System in southern India.

Design: Observational case series.

Methods: Manual waste audits, purchasing data, and interviews with Aravind staff were used in a hybrid environmental lifecycle assessment framework to quantify the environmental emissions associated with cataract surgery. Kilograms of solid waste generated and midpoint emissions in a variety of impact categories (eg, kilograms of carbon dioxide equivalents).

Results: Aravind generates 250 grams of waste per phacoemulsification and nearly 6 kilograms of carbon dioxide-equivalents in greenhouse gases. This is approximately 5% of the United Kingdom's phaco carbon footprint with comparable outcomes. A majority of Aravind's lifecycle environmental emissions occur in the sterilization process of reusable instruments because their surgical system uses largely reusable instruments and materials. Electricity use in the operating room and the Central Sterile Services Department (CSSD) accounts for 10% to 25% of most environmental emissions.

Conclusions: Surgical systems in most developed countries and, in particular their use of materials, are unsustainable. Results show that ophthalmologists and other medical specialists can reduce material use and emissions in medical procedures using the system described here.

Figure 1

Downstream material flow diagram for the surgical supplies used in Aravind’s phaco-emulsification cases (CSSD = Central Sterile Services Department; IOL = intraocular lens; RO = reverse osmosis).

Figure 2

Lifecycle environmental effects of an average phacoemulsification at Aravind Eye Hospital in Pondicherry, India. The mean value of total emissions is shown at the top of each impact category column. Costs do not include staff salaries, the IOL, water use, overhead, or capital equipment (* = pharmaceuticals were calculated using economic data in a U.S.-based model; CFC = carbofluorocarbons; CO₂ = carbon dioxide; CTU = cumulative toxicity unit; h = human; e = environment; eq = equivalent; MJ = megajoules; O₃ = ozone; PM2.5 = particulate matter less than 2.5 μm in diameter; USD = 2014 U.S. dollars).

Figure 3

Effect of surgical duration on energy use (grid electricity and diesel generators), greenhouse gas emissions from energy use, and costs for a single phacoemulsification at Aravind Eye Hospital (GHG = greenhouse gas; kWh = kilowatt hour).

Figure 4

Effect of patient throughput and material reuse on total greenhouse gas emissions and per case cost (2014 U.S. dollars) for phacoemulsification at Aravind Eye Hospital; does not include emissions associated with energy use, building construction, or capital equipment such as the phacoemulsification machine (CO₂-e = carbon dioxide-equivalent; GHG = greenhouse gas).

Figure 5

Comparison of greenhouse gas emissions for phacoemulsification in the U.K. and at Aravind based on economic subsectors, modified from Morris et al., to account for different study boundaries (* = Aravind’s laundry services are included in the Procurement - Water category; CO₂-e = carbon dioxide-equivalent; GHG = greenhouse gas).