Sustainability in Ophthalmology: A Look at Green Practices in Place ‘Down Under’ and Around the World

Climate change, and its potentially catastrophic effects, are now clearly observable and beginning to be felt all over the world. More unpredictable and extreme weather events, increased prevalence of disease, food scarcity and even political unrest are examples of this. The reality is, even in the best case scenario, our planet is going to be about 2.5 degrees Celsius warmer by the end of the century.

Health Care and Our Carbon Footprint

Many of us are aware of the major emissions contributors in our lives. We all know we need to use our cars less. Reduce, reuse and recycle more. We’re most likely familiar with industries that are big polluters as well. Energy and intensive agriculture being at the forefront. 

But are we conscious of the contribution the health sector makes toward global emissions? The figures may surprise you. Globally, health accounts for around 5% of all greenhouse gas (GHG) emissions. The U.S. has the highest carbon footprint from health, sitting at 10% of total emissions. While in the U.K. it’s around 5%, and within New Zealand and Australia, numbers range from between 4-7%.1 These stats should be (and are), a cause for concern. 

Dr. Cassandra Theil, a leading researcher in sustainable healthcare, explained it well at the recent plenary session at RANZCO Brisbane 2022 where she was a guest speaker. “We have finite financial and environmental resources. In healthcare, we have been given a pass quite often (on both counts), when actually we can’t afford, financially or environmentally (or socially for that matter), to keep doing things the way that we have been,” she said.

Ophthalmology is as guilty as any other department here, too. Cataract treatment, in particular, is a huge emissions producer. Using existing practices (those employed in most affluent Western countries), a single cataract surgery emits around the same amount of CO2 as the average person generates in a week. Most of this is taken up by transport and energy costs (both in the procurement of materials and commuting of patients and staff), but there is a great deal of waste involved also. According to 2011 estimates, Dr. Theil shared that drug waste from cataract surgery in the U.S. alone results in an unnecessary 23,000-105,000 metric tonnes of CO2 emissions per hospital. That’s equivalent to driving the length of that country 4,600-51,000 times!

But What Can We Do About It?!

So, we know the scale of the problem, the question is what is being done to fix it? Well, there is action. While tackling climate change can seem overwhelming, especially from a health perspective, there are emerging success stories we can aspire to and learn from.

We touched briefly on the huge carbon footprint generated by modern cataract treatment techniques like phacoemulsification. There are, of course, alternatives to this method. Manual small incision cataract surgery (MSICS) has been found to be a safe and effective technique for cataract extraction. It’s also considerably better for the environment. Phacoemulsification machines use more energy, create more waste and are 1.4 to 4.7 times more expensive than MSICS. Unsurprisingly, MSICS is used predominantly in developing countries where cost effectiveness is of the utmost importance.1

Lessons From the Developing World

In many ways, developing nations are in fact leading the world when it comes to sustainable ophthalmological practices.

A particularly inspirational example of this can be found coming out of India. The Aravind Eye Care System (AECS) is able to perform phacoemulsification procedures (to the same exacting standards of safety and efficacy as expected in the West), at a fraction of the cost and with drastically reduced emissions. This is mostly due to their high volume approach (performing up to 1500 cataract surgeries a day) which minimizes energy and electrical footprints. They also sterilize and reuse materials extensively. Phacoemulsification undertaken at AECS results in the generation of around 6kg CO2eq, compared with 130 kg CO2eq per procedure in the U.K. That’s around a 95% reduction in emissions!1

So with the proven effectiveness of the AECS’ treatment model (and given the urgency of the climate crisis), one could be forgiven for wondering why these techniques have not been adopted worldwide? 

Dr. Jesse Gale, an ophthalmologist from Wellington, New Zealand, and RANZCO chair of sustainability, muses much the same.

“The carbon footprint of cataract surgery in India is about 5% of the footprint in the U.K. or New Zealand, and yet the safety and quality of their surgery is maintained (i.e, infection rates, visual outcomes). So, they save huge amounts of money, have an incredible work rate, and emit far less carbon, which are all things we could aspire to in our practice. It is interesting to think about the barriers that stop New Zealand ophthalmologists from immediately practicing like Indian ophthalmologists.”

Indeed. While existing regulations are ostensibly in place with patient safety in mind, and liability (particularly in the U.S.) is a factor for manufacturers, perhaps it is time we readjusted our expectations and ideologies? Both as patients and practitioners, to be more in line with sustainable surgical practices in other parts of the world?2

Sustainable Ophthalmology in the Antipodes*?

On that note (and being from the region myself), I wanted to know where exactly things were Down Under,** in terms of coming up with and implementing a strategy to mitigate unnecessary emissions in the ophthalmology sector…

Aotearoa/New Zealand and Australia are both renowned for their spectacular scenery and relatively untouched natural beauty. New Zealand, in particular, has been the poster child for the “clean and green” image for decades. But are these accolades really warranted? What policies or actions are these countries implementing across the board (health and ophthalmology included) toward a more sustainable future? Because despite their relative geographical isolation Down Under, neither is excluded or exempt from the global existential threat posed by anthropogenic climate change.

Well, it seems their resident ophthalmologists are not only keen to ensure your eye health is in tip top shape to take in all those breathtaking views, but they also want to make certain that it’s done sustainably to preserve those vistas for future generations.

Let’s Survey the Ophthalmological Landscape of the Area

The first steps (which are well under way), center on assessing/measuring emissions, as well as gauging the sector’s willingness to be proactive in tackling the issue. 

A recent survey conducted by RANZCO (Royal Australian and New Zealand College of Ophthalmologists) suggests whilst ophthalmologists in the region are generally on board and up to speed with what’s required, there are some notable gaps around the implementation and incentivization of sustainable practices. 

Climate Change Skepticism in Eye Care

The survey also revealed a not insignificant minority of ophthalmologists who disagreed with statements on anthropogenic climate change in general. In New Zealand, some 15 to 19% disagreed that climate change was urgent, or that climate change required mitigation, or that climate change would affect health. A larger minority of 19 to 23% disagreed with the proposal that ophthalmologists or RANZCO should advocate in the domain of climate change.3 Over the ditch,*** the numbers were even higher, with up to 28% of practitioners expressing opinions of this nature.4

While this is concerning, Dr. Gale, one of the survey’s co-creators, says it’s important to focus on the positives. 

“I was a bit surprised that the level of concern around climate change was lower in ophthalmologists than the general population of New Zealand and Australia,” said Dr. Gale. “The surveys showed that female, urban and younger ophthalmologists had more concern about climate change and more appetite for action to address it, so our profession is catching up. I don’t think there is a significant roadblock or barrier to progress in this domain, as even the most climate-denying individuals will not affect the momentum of the college or society generally. Generally, there is 70% agreement that climate change needs action from the health sector, which is fairly solid agreement on any issue.”

Coordinated Central Government Policy, High-level and Top-down Changes Required

In New Zealand, efforts are being made to optimize sustainability in outpatient clinics, where patient travel accounts for 10 to 16% of emissions. Virtual clinics, combining one-stop surgical clinics with community postoperative checks, and community optometry clinics for low-risk glaucoma are some strategies being used to minimize unnecessary travel. More investment in cloud-based technologies to support telemedicine (online consultations/diagnosis) would help to reduce unnecessary travel. 

However, most of these initiatives are not supported by current private practice funding, or prioritized by district health boards (DHBs). Unless sustainability initiatives are encouraged and used as performance indicators, ophthalmological practices are going to lack the motivation to implement them.3

“I have been very pleased by the encouragement and enthusiasm from the RANZCO board, so I feel our professional organization is moving in the right direction. Within our public hospitals (DHBs) in New Zealand, I know that sustainability officers are very busy, mostly with the first task in the process of measuring emissions.  There was a brief government statement that all public sector work would be carbon neutral by 2025, but there is a lot of work to be done before that looks realistic. The Greener NHS project in the U.K. is much further along this pathway, with a goal of neutrality in 2045, and their efforts lead the way in this field,” pointed out Dr. Gale.

Following the UK’s Lead 

“The British National Health Service is a massive public health system with central governance and funding and they have been working towards a sustainable system for years longer than us,” said Dr. Gale.

“The Australian system is more fragmented, with more ophthalmology delivered in private settings and separate state and local public ophthalmology services, so it is less easy to create a unified approach and to motivate decarbonization. In the New Zealand system, our 20 DHBs are to come under one operational body in the near future, and a carbon neutral public sector is now an urgent priority, so the work to decarbonize health care is rapidly accelerating,” he continued.

Measuring, Made Easier!

New technologies with the potential to help optimize resource use and reduce unnecessary emissions are emerging within the ophthalmology sector as well. Eyefficiency, an application which can be used to estimate carbon footprints, is proving to be particularly useful.

This application was used as the primary measurement tool in a recent study which aimed to assess the carbon footprint of cataract surgery in Wellington, New Zealand.5 The study examined emissions generated from phacoemulsification procedures within four hospitals, two public and two private. It focussed on four main areas: (1) power consumption, (2) procurement of disposable items and pharmaceuticals, (3) waste disposal emissions and (4) travel. 

The study found cataract surgery in Wellington, New Zealand had a similar carbon footprint to that seen in the U.K. and other developed nations. The average emissions produced by cataract surgery in the region were estimated to be around 152kg CO2. This is equivalent to burning 62 liters of petrol, and would take 45m2 of forest approximately one year to absorb. Extrapolate this data across the 30,000 cataract surgeries performed annually in New Zealand, and we wind up with approximately 4,500 tonnes of CO2. This would take 134 hectares of forest roughly one year to absorb!

The majority of emissions were from procurement, mostly of disposable materials, and the second largest contribution was from travel (driving). Emissions from electricity were much less significant in New Zealand (1.8kg CO2 e compared to the U.K. 66kg CO2 e). This is predominantly due to the majority (82%) of the country’s electricity coming from renewable sources such as hydroelectricity. New Zealand government policy aims to increase the renewable energy sector to the theoretical maximum by 2030, so this is an area where the small island nation is really leading the way. 

While there may be some discrepancy in emissions measurements for procurement (measurements were based on 2011 data for production and supply of general medical equipment, relying on cost to calculate emissions and don’t necessarily take into account product life cycles, etc.), this is quite clearly an area where New Zealand can work on reducing emissions. The study points to the importance of The Pharmaceutical Management Agencies (PHARMAC) role here in future procurements. Their newly designated role to bulk-purchase surgical supplies represents a major opportunity both to improve measurement of emissions related to procurement, and to leverage reductions in emissions during contract negotiations. 

More innovative commuter options are suggested to mitigate travel emissions. Examples of subsidy partnerships between local government and public transport such as the BusinessEcoPass initiative in Boulder County, Colorado, U.S., are seen as viable incentives. Hospitals should also invest in facilities to make active modes of transport such as walking or cycling more attractive (e.g., more safer cycle ways, walking paths, etc). Active commuting not only leads to reduced emissions and improved air quality, but an active population leads to better physical and mental health. Reducing demand for healthcare is itself a key component for a low carbon health system.

The study provides a useful benchmark for comparing cataract surgery in New Zealand with other hospital systems around the world. It highlights areas where emissions reductions can be targeted (namely travel and procurement), as well as the requirement for more complex systemic changes. It calls for comprehensive top down sustainability policy from central and local government, as well as changes in behavior from individual practitioners.

COVID-19: Sustainability Setback or Opportunity?

It’s important to remember all of this has been unfolding against a backdrop of the global COVID-19 pandemic. Many sustainability initiatives (especially within the health sector) were put on the back burner in favor of stricter hygiene practices. Personal protective equipment (PPE) was in such demand that supply chain issues were experienced worldwide. Although necessary, increased use and production of PPE obviously creates more waste and emissions. It’s important that we learn from this crisis and innovate for the future. As we know, pandemics are also a symptom of climate change, and it’s unlikely this will be the last.

Many innovative sustainability strategies actually emerged during the pandemic. These can and should be applied to healthcare moving forward. Telemedicine, virtual reality, artificial intelligence, and even smartphone apps for testing vision, are all technologies which can be applied not only to minimize risk in terms of spreading disease, but also to reduce emissions by limiting unnecessary hospital visits. Use of multidose pharmaceuticals should be encouraged over single-use products. Reusable or biodegradable medical equipment has a minimal environmental footprint, and production could be scaled up and materials stockpiled for future crises.6

“Technology will help with creating more reusable things, like reusable drapes, gowns, phaco tubing and cassettes, and surgical blades. There are companies that collect single-use blades and check, sharpen and sterilize them, then sell them back cheaper than a brand new one. As carbon pricing starts to come in, reusable technologies will suddenly be much cheaper than single use items,” said Dr. Gale, who is somewhat of an innovator in this area himself, with a research interest in producing inexpensive 3D printed medical devices.

“We do need to learn quickly that safety does not always require single-use disposable PPE.  Reusable PPE is very safe and effective in most situations, and this could be an area where technology can help. Remember when we found out that masks can be washed in the washing machine at least 10 times? Amazing how many [disposable] masks could have been avoided.  We have learnt some things from COVID that are helpful lessons for future sustainability, like considering flights carefully, working from home can be effective, and telemedicine can reduce resource consumption and travel,” he continued.

Where to From Here?

In summary, it might be useful to look back at some of the key points and comments from the RANZCO Brisbane 2022 plenary. 

Climate change and sustainability remains a broad reaching conundrum. It’s easy to feel overwhelmed, or that our actions as individuals are insignificant. But if our efforts are targeted and unified, they can still be effective. Climate change affects all of us, and so it is everyone’s responsibility to do whatever we can to mitigate it. Doctors in particular enjoy a position of influence and leadership in society, and have a responsibility to act for public health. There is growing acceptance in the ophthalmology community that all doctors should have a voice to support a healthy climate future through decarbonizing healthcare and adapting health systems.

For RANZCO itself, Dr. Gale outlined some key areas where the College can actively seek to mitigate climate change. He talked about advocacy and collaboration with other colleges and industry, both locally and internationally, to establish sustainable practice guidelines. Continued engagement with trainees and fellows, especially around developing tools and systems for accurately measuring emissions, will continue. Corporate sustainability means measuring the footprint of College activities and investments, and acting to divest from polluting industries and minimizing the emissions from college activity. Finally, he touched on the importance of continually looking to innovate in ways that are more sustainable, but that don’t compromise on the quality of treatment or patient safety.

*New Zealand and Australia are sometimes called the “antipodes” because they are  on the other side of the earth from Britain.

**The term “Down Under” refers to the relative geographical location of Aotearoa/NewZealand and Australia at the bottom of the global atlas.

***“Over the ditch” is an affectionate colloquial expression used by Kiwis (New Zealanders) and Ozzies (Australians) to refer to their respective neighbors’ location on the other side of the Tasman Sea, a stretch of water that divides the two countries.

Editor’s Note: A version of this article was first published as the Cover Story in CAKE magazine Issue 13.


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  2. Thiel CL, Schehlein E, Ravilla T, et al. Cataract surgery and environmental sustainability: Waste and life cycle assessment of phacoemulsification at a private healthcare facility. J Cataract Refract Surg. 2017;43(11):1391-1398. 
  3. Chandra P, Gale J, Murray N. New Zealand ophthalmologists’ opinions and behaviours on climate, carbon and sustainability. Clin Exp Ophthalmol. 2020;48(4):427-433. 
  4. Gale J, Sandhu SS, Loughnan MS. Australian ophthalmologists’ opinions on climate and sustainability. Clin Exp Ophthalmol. 2020;48(8):1118-1121.
  5. Latta M, Shaw C, Gale J.The carbon footprint of cataract surgery in Wellington. New Zealand Medical Journal. 2021;134(1541):3.
  6. Thiel C, Schuman JS, Robin AL. Severe Acute Respiratory Syndrome Coronavirus Disease 2019: More Safety at the Expense of More Medical Waste. Ophthalmol Glaucoma. 2022;5(1):1-4.

Dr. Jesse Gale is an ophthalmologist in Wellington, New Zealand. He chairs the RANZCO sustainability committee and practices mostly in glaucoma and neuro-ophthalmology. He has a range of research interests including sustainable ophthalmology and inexpensive 3D printed medical devices, biomechanics and pressure gradients affecting the optic nerve, and electrophysiology of optic neuropathy. [Email:]

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