Measures needed to reduce impact of cataract surgery’s high carbon footprint

Health care procedures are a large contributor to carbon emissions throughout the world. Presently, surgeons and health care organizations are analyzing the effects of carbon emissions from cataract surgeries and how to decrease the carbon footprint of these procedures.

In 2013, researchers from the United Kingdom published a benchmark component analysis study on the carbon emissions per cataract surgery. Daniel S. Morris, FRCSEd(Ophth), a consultant ophthalmologist at the University Hospital of Wales, U.K., and lead author of the study, noted one cataract surgery had a carbon footprint of 181.1 kg carbon dioxide equivalent (CO₂ eq).

Cataract surgery carbon footprint

The study included 2,230 patients treated for cataracts in Cardiff. The procedures had a total carbon footprint of 405.4 tons of CO₂ eq. Putting this into context, the average carbon footprint for one U.K. resident per year is generally estimated at 10 tons of CO₂ eq, according to the study.

“There is a lot of waste with every cataract surgery. In our study, we were looking at three different areas for each procedure. One was the energy use in the hospital, the second was the travel made by patients and staff, and the third was the procurement and disposal of equipment for the surgery (instruments, IOL, etc.). We saw, potentially, that there was a lot of energy being used during a surgery and by getting to and from a procedure, but the procurement section came out the highest per procedure,” Morris said.

The procurement of supplies was the highest carbon emission producer for the entire cataract procedure, totaling 54% of the total emissions for each surgery, Morris said.

Image: Robin AL

Packaging adds waste

The packaging of supplies, the ordering model employed by hospitals for surgical supplies and the materials that come with each supply bundle all contribute to the total carbon footprint of surgery.

“Right now, we will put a purchase order in for just a couple of intraocular lenses at a time, and they will be sent out in one delivery truck. But what we should be doing is thinking ahead by a month and ordering 1,000 lenses, not just two or three, so we would just have one truck coming out a month and not 50 trucks a month,” Morris said. “There is also a huge amount of packaging for just one tiny lens, which is a requirement from the regulators. There is a 70-page booklet inside of each lens package, and that is really not required by us. We need to lobby the regulators with our industrial partners to change this, and that would make a big difference.”

“Even something as small as multiple patient trips to a hospital for preoperative and postoperative examinations can increase the carbon footprint for a single procedure,” he said.

Patients make four to five visits to a hospital for pre- and post-surgery evaluations, Morris noted. With thousands of patients making these trips each year, it may make sense for more institutions to offer cataract surgery on a “one-stop basis.”

“They would be seen in the morning by nurses, who perform a pre-assessment, and would then have surgery in the afternoon and be discharged back to the optometrist after that,” he said.

A call to increase sustainability

The Royal College of Ophthalmologists published an Ophthalmic Services Guidance in 2013 that urged the United Kingdom to put more of an emphasis on sustainability in ophthalmology. The guidance said that cataract surgeries are an ideal area in which to “target carbon reduction strategies.”

About 300,000 cataract surgeries are performed in the United Kingdom annually, the guidance said.

“To date, various studies have demonstrated potential opportunities for the execution of sustainable eye care. Somner et al highlighted that during cataract surgery, small-incision surgery produced less CO₂ emission than phacoemulsification techniques. Similarly, it has been postulated that simple technological strategies such as re-designing of taps used for surgical scrubbing can significantly decrease the amount of water wasted during surgical procedures,” according to the guidance.

Morris suggested the cataract surgery model employed by the hospitals in the Aravind Eye Care System in India could be a way to possibly cut back on the carbon footprint for the procedures.

Aravind Eye Care System

Cassandra L. Thiel, PhD, a postdoctoral associate of sustainable health care engineering at the University of Pittsburgh, published a preliminary poster detailing the Aravind Eye Care System’s cataract surgery model and noted that one phacoemulsification surgery resulted in a carbon footprint of just 15 kg CO₂ eq.

The reduced carbon footprint can be attributed to several key differences in the way surgeons complete procedures in Aravind hospitals, she said.

“The main reason is they use almost all reusable materials. It is not just the stainless steel instruments they use that tend to be reusable — it is the gowns and the larger drapes. Their outcomes and infection rates are just as good, if not better, than the United Kingdom and United States. It is an effective way to use these materials for these surgeries. They do this mainly for cost savings, but the more times you reuse something, the more this drastically reduces the carbon footprint,” Thiel said.

To minimize wait time for patients, Aravind surgeons operate on two tables. While operating on a patient, two scrub nurses and a circulating nurse assist the surgery and at the same time prep the next patient on the second table. This enables the maximum use of equipment and reduces overhead costs per patient, Thiel said.

Much less waste

Each surgery completed at Aravind results in an average 0.25 kg of waste, of which two-thirds is recycled. One-fifth of the total amount of waste per surgery is the single-use patient face drape, and one-fourth of the waste originates from the packaging and directions included with the IOL, according to Thiel.

Additionally, instruments used in the Aravind system will be autoclaved and sterilized for 30 minutes and used again right away. The instruments are not dried before their next use. At the end of the day the instruments go through a full 1-hour autoclaving process, are dried and are then stored overnight, Thiel said.

“You are saving energy and increasing the overturn of the instruments with this method,” she said.

The same surgery completed in the United States results in about 10 times the amount of waste when compared with the Aravind model, she said.

“That is what we are trying to explore in America, how far we can get within existing policies and what can we work toward changing. There is reusable equipment available, but there is a whole other mess of questions that arise when you get into switching to reusable equipment. You have to look at third-party suppliers that can help sterilize these things, what the cost is per system, and if you may need more space to store those systems — space can be limited in a hospital. Those are options and certainly available in our framework,” Thiel said.

Reducing American operating waste

American operating rooms should look into what they can integrate from the Aravind method to reduce waste and the carbon footprint of cataract surgery, Alan L. Robin, MD, OSN Glaucoma Board Member, said.

“We can re-evaluate and compare our work to those at Aravind and other institutions. We should follow the dictum of ‘first do no harm.’ We do not want to create additional risks for our patients, yet we do not need additional and wasteful regulations forcing us to be non-green. We have to look at our habits, from both a ‘green’ and ‘financial’ perspective, as being less green is expensive long term,” he said.

Those in the medical landscape need to evaluate the “absolute minimum of regulations” that would assure positive patient outcomes, he said.

However, many of Aravind’s cost- and energy-saving techniques cannot be integrated into American operating rooms due to stricter regulations and an unwillingness to do so, Joel S. Schuman, MD, FACS, OSN Glaucoma Board Member, said.

Schuman and Robin are among co-authors with Thiel on the poster she presented at the American Ophthalmological Society meeting in Colorado Springs, Colorado.

The Aravind surgeons, for example, often do not change surgical gloves in between procedures. Rather, the surgeons wash them off and use a sanitizing solution on their gloves between surgeries. Schuman said this is likely something that will never be allowed in the United States, despite the low infection rates exhibited in the Aravind system.

Greater emphasis on reusable items

However, there are many facets of the Aravind system that could be integrated into American operating rooms, Schuman said.

Putting a greater emphasis on employing reusable items could go a long way in reducing the carbon footprint. Making a switch back to reusable gowns, instead of the now widely used paper or plastic gowns, would reduce waste and may even reduce costs for a hospital in the long run, Schuman said.

“It takes energy to save energy. What I mean by that is, you need an administration that is committed to reducing the amount of waste that we produce and working with the companies that produce what we use, working with the hospital infrastructure in order to intelligently choose the materials, equipment and supplies that we will be using in the operating room,” Schuman said.

Re-evaluate governmental regulations

Robin said several governmental regulations should be re-evaluated because many are “reactive and not evidence based.”

“The single use of pharmaceuticals, anesthetic supplies and irrigating fluid containers not only creates waste, which is expensive, but also potentially could damage our planet by contaminants getting into our ground and drinking water, to plastics that are not biodegradable. Multiple items used could, if properly applied, be reusable. Likewise, drapes and gowns are paper, rather than laundered clothes,” he said.

Waste, the environment and the health care dollar should all be connected, Robin said. The surgical industry has looked at the amount and ecological effect of waste from all types of surgery, but has yet to specifically evaluate the costs.

“If we really want to be cost-effective, unnecessary waste must be eliminated,” he said.

Cutting down on items

Increasing recycling rates and using more reusable devices are ways to cut down on the waste stream and shrink the carbon footprint of each procedure. However, there are other less obvious techniques that can cut down on the carbon footprint of operating rooms.

Reusing pharmaceutical items or sending them home with a patient can also reduce the carbon footprint of each procedure, Thiel said. However, there are regulations in place that do not allow this practice. For instance, if eye drops are used in a surgery, the entire bottle must be disposed of after the procedure is finished, even if the bottle is not empty.

These drops could be sent home with a patient in case they are needed later, Thiel said, or they could be saved in a sterile environment for the next procedure instead of opening a new bottle of the same drug.

“We think it would be relatively easy to analyze the sterility of all these things and say this regulation is not necessarily protecting patient safety like we expect it to. The regulation is to keep things safe and sterile, but with things like drops, you will know if they are contaminated. The idea is you can use those drugs on multiple patients or at least send those drops home with the patient if it is something they can use. That will not adversely affect quality, but will drastically improve the cost per case and waste generation per case,” she said.

Effort goes a long way

One person and one hospital can make a difference when it comes to reducing waste and the carbon footprint of cataract surgery, Schuman said.

He said regulations should be evaluated to see if waste can be reduced for each surgery, but in the end it will take increased effort and energy to make an impact.

“I think the important thing is we are all responsible for the waste we produce and the health of the planet. While it seems kind of trite, you can make a difference. A single person can make a difference, and that single person certainly adds up when you’re talking about one of the most commonly performed procedures in the world,” Schuman said. – by Robert Linnehan

• References:
• Morris DS, et al. Eye (Lond). 2013;doi:10.1038/eye.2013.9.
• Somner J, et al. J Cataract Refract Surg. 2009;doi:10.1016/j.jcrs.2008.09.026.
• The Royal College of Ophthalmologists, Ophthalmic Services Guidance. Sustainability in Ophthalmology Executive Summary. https://www.rcophth.ac.uk/wp-content/uploads/2014/11/2013_PROF_222_Sustainability-in-Ophthalmology-May-2013.pdf.
• Thiel C, et al. Green cataract surgery: Waste generation and carbon footprint of phacoemulsification at Aravind Eye Hospital in Pondicherry, India. Presented at: American Ophthalmological Society meeting; May 19-22, 2016; Colorado Springs, Colo.

• For more information:
• Daniel S. Morris, FRCSEd(Ophth), can be reached at University Hospital of Wales, Heath Park, Cardiff, CF14 4XW, United Kingdom; email: dsm@doctors.org.uk.
• Alan L. Robin, MD, can be reached at Glaucoma Specialists, 6115 Falls Road, Suite 333, Baltimore, MD 21209-2226; email: arobin@glaucomaexpert.com.
• Joel S. Schuman, MD, FACS, can be reached at NYU Langone Medical Center, 660 1st Ave., New York, NY 10016; email: joel.schuman@med.nyu.edu.
• Cassandra L. Thiel, PhD, can be reached at University of Pittsburgh, 4200 Fifth Ave., Pittsburgh, PA 15260; email: clthiel@gmail.com.

Disclosures: Morris, Robin, Schuman and Thiel report no relevant financial disclosures.

Would using more ‘green-friendly’ reusable items and fewer single-use disposables in cataract surgery settings be cost-effective?

A challenging transition

The cost-effectiveness of transitioning from single-use to reusable surgical instrumentation in ophthalmology is challenging to elucidate, namely because with disposable instruments you have a predictable fixed cost. However, the potential charges with reusable equipment beyond the initial purchase price can be unpredictable due to indefinite life expectancy, quicker than expected wear-and-tear, or even worse, instrument malfunction or damage. More importantly, however, such a decision requires a thoughtful analysis of other factors besides cost, which may ultimately impact our patients’ operative outcomes.

First, one must consider durability issues. Reusable instruments inevitably degrade over time, requiring frequent maintenance and oftentimes replacement. With repetitive use and sterilization, these tools may be inadvertently damaged due to their delicate nature and rendered not as effective intraoperatively.

Second, the sterilization process itself must be considered as there is a small chance of insufficient cleaning and contamination with each cycle of use. In comparison, the surgeon can be confident that with single-use instruments, they are working with sterile equipment every time. Furthermore, instrument sterilization is a time-consuming process that may result in delays in operating room turnover times, thus hampering surgical efficiency.

Third, having reusable items restricts a surgery center’s flexibility in accommodating to different surgeon preferences. Not all surgeons are equally skilled at using the same instruments, and having an assortment of various disposable items available may be more ideal to a center than asking all staff to acclimate to a particular reusable product.

For these reasons, I believe declining to replace single-use instruments with reusable ones is the more preferable and cost-effective scenario.

Ehsan Rahimy, MD, practices with the Vitreoretinal Disease and Surgery Division of the Palo Alto Medical Foundation in Palo Alto and San Carlos, California. Disclosure: Rahimy reports no relevant financial disclosures.

Sterilization may cause issues

Years ago, reusable items dominated the ophthalmic surgical field. Reusable phaco machine tubing, reusable cannulas, reusable IOL loaders and more were the norm. Cleaning and sterilizing lumened instruments is not only time consuming but if detergents or enzymatic cleaners are not thoroughly rinsed, residues may cause toxic anterior segment syndrome (TASS).

TASS is a noninfectious, sterile, acute postoperative inflammation affecting various structures within the anterior segment. Typically, TASS presents within 24 hours after cataract surgery, leading to decreased vision and pain. A fibrinous inflammation in the anterior chamber is the hallmark.

While investigations did not find a single source to be the cause during the peak of the TASS breakout 10 years ago, issues with sterilization, detergents and enzymatic cleaners were suspected to be contributing factors. As a result, a strong shift to single-use, disposable items was made.

Currently, many of the IOL loaders are single-use or come preloaded in disposable delivery cartridges. Cannulas used for the injection of viscous products such as OVDs are packaged with disposable cannulas to avoid potential clogging of the lumen. There is less risk for contamination by adhering to single-use devices. Fortunately, some items in the operating room can be recycled, whether glass or plastic.

From a patient safety perspective, minimizing the risk of TASS or endophthalmitis by the use of single-use devices is paramount even though it may not be as “green-friendly” as we want.

Cynthia Matossian, MD, FACS, is an OSN Cataract Surgery Board Member. Disclosure: Matossian reports no relevant financial disclosures.