ESCRS - Newsmaker Interview with Dante Luis Buonsanti MD
ESCRS - Newsmaker Interview with Dante Luis Buonsanti MD

Newsmaker Interview with Dante Luis Buonsanti MD

EuroTimes Editor-in-Chief Sean Henahan spoke via Zoom with Dante Luis Buonsanti MD, the young Argentinian ophthalmologist who developed the new ESCRS IOL Calculator.

First, could you remind us of the purpose of the IOL calculator project? Why did you think this was necessary?

The purpose was to bring together all the excellent online formulas into one convenient location. There are at least 20 separate formulas for IOL power calculation online. They are updated regularly, either with AI or new data, new IOL constants, etc. On the other hand, we have expensive biometry machines used to calculate the IOL power, but those biometers are not connected to the internet for various reasons.

New online formulas come all the time, while the biometers use older formulas that are not updated as much. Before our tool was developed, you would do the biometry and then visit four or five sites, entering the exact same data each time. Or you might decide to use one or two formulae to save time, and do the surgery after you choose the IOL power, when maybe you might have gotten a better result with another formula. We wanted to help surgeons by providing an easy way to load the patient data just one time for multiple calculator sites.

Could you tell us how you came to work with the ESCRS on this project?

At first, I thought I would do a personal web page called I wrote to all the formula authors, including Kenneth Hoffer and Graham Barrett, to explain my intention and ask permission to include their formulas. Kenneth Hoffer connected me with the ESCRS, and the board liked the idea. They wanted to make a calculator, but they didn’t know what to do. It was the right time and the right place. The ESCRS team included Oliver Findl, Nino Hirnschall, Filomena Ribeiro, and Miguel Raimondo. We met regularly and started to polish the idea, adding features, finally resulting in the finished product that is now online.

Did you encounter any resistance to the idea of aggregating the formulas in one website?

There may have been some concern at first when I started emailing people. Perhaps they had questions about the purpose, maybe some concern about errors or liability. But once the ESCRS came on board, we had no problems. All the authors were happy with the idea and glad to participate.

The site uses a technique called webscraping. This sounds something like Google Travel, where I can enter my flight requirements and find out all the options from the various airlines. It is exactly like that. Our site uses no internal calculations. When you enter the data, it goes to the various sites and returns to our site with the results. Entering data once saves time and reduces the chances of typing errors. If the different sites update, we update ours. Most of the formulas are not published, so the only way of getting the results is to use these online calculators. Also, our site makes doctors aware of the existence of all these formulas they may not even know about.

The site has been online for a little while now. Are you getting user feedback, thinking about making any changes?

The ophthalmology community really seems to accept and like it. The traffic has been huge. Next, we will launch a toric IOL version, then add a calculator for post-refractive eyes that uses the newest formulas.

What are your thoughts on the evolution of IOL power calculators over time?

The tools we have now are great. That is why cataract surgery is now refractive surgery. We are getting close to perfection. I think we may have reached the limit for standard eyes, with 85% or more getting within +/-0.5 D of the target. Biology plays a role, so I expect we will always have some outlier cases. We are getting better with more complex cases, such as high astigmatism and eyes that have undergone previous refractive surgery, but we still have a lot of work to do.

The ESCRS IOL Calculator is free to all ophthalmologists at


Sean Henahan
Sean Henahan


Thursday, December 1, 2022


IOL calculator