January 2017




All about IOL calculations

Advanced technology sharpens astigmatic outcomes after cataract surgery

by Vanessa Caceres EyeWorld Contributing Writer

The Callisto

The Callisto as seen by the surgeon during the procedure Source: Oliver Findl, MD

5 tips to maximize technology use

The advanced technology that refractive cataract surgeons have at their disposal can help sharpen outcomes for astigmatic patients, according to physicians well versed in the technology.

From intraoperative aberrometry to femtosecond lasers to guidance systems to toric IOLs, patients experience better outcomes—and surgeons find that the various technologies work synergistically.

“The technology has made everything more accurate,” said Robert Weinstock, MD, Eye Institute of West Florida, Largo, Florida. Refractive enhancements for Dr. Weinstock now occur in fewer than 4% of patients. “I attribute a lot of that to great biometry but also to the utilization of these devices and software to make sure astigmatism management is as accurate as possible.” Advanced refractive technology also eliminates some of the preoperative steps once needed, said Oliver Findl, MD, Department of Ophthalmology, Hanusch Hospital, Vienna, Austria. For instance, preop marking of the eye was once crucial—and occasionally forgotten. Now with the Callisto system (Carl Zeiss Meditec, Jena, Germany), it isn’t necessary, he said. Various technology he has available now can transfer data among his systems without the risk of human transcription errors that were sometimes made before.

Technology such as intraoperative aberrometry can be a “tiebreaker” in driving final surgical decisions, Dr. Weinstock said. He has an ORA System (Alcon, Fort Worth, Texas) and uses it to help assess his laser-created arcuate incisions and whether or not to modify them. He also uses ORA to guide toric IOL placement. Published reports have shown that the use of intraoperative aberrometry can improve results by 5% to 10%, said Stephen Lane, MD, medical director, Associated Eye Care, and adjunct clinical professor, University of Minnesota, Minneapolis. That said, Dr. Lane encourages cataract surgeons to make the leap to using toric IOLs in astigmatic patients even if they don’t have all of the cutting-edge technology now available. “While we have incredible tools to help us, we don’t need all of those tools for excellent results. You can improve good results to become excellent, but you shouldn’t sit on the sidelines waiting to use toric IOLs because you don’t feel the technology is good enough yet or is too expensive. … The first step is being involved in implanting toric IOLs,” he said.

Dr. Lane gave the analogy of prescribing glasses for a patient and always making sure to address a patient’s astigmatism—it makes sense that a cataract surgeon would give the same consideration when implanting IOLs in patients by addressing astigmatism.

It’s important to look beyond outcomes when you select technology for astigmatic correction, Dr. Findl said. In fact, having advanced technology to help treat astigmatic patients has not really changed his outcomes. He was involved with a trial that compared manual markings with the Callisto; although the Callisto did show more precision, it was not a significant difference. “At the end of the day, if you do manual markings with a focus on precision, it works well,” he said. Consider other ways that technology may help you, such as by making surgery more efficient or eliminating some human errors.

As you start to incorporate advanced refractive technology into your cataract surgery, keep these pearls in mind for achieving better astigmatic outcomes.

Tip 1: Get tech-savvy—and have your best technicians get savvy as well

Use of advanced refractive technology requires a solid working knowledge of things like femtosecond lasers and the interaction between preoperative and intraoperative systems. Get the proper training for everyone involved.

Tip 2: Have backup plans in place

Even the best technology can fail, and that’s why Dr. Weinstock has patients marked ahead of time with the RoboMarker (Surgilum, Wilmington, North Carolina), in case laser technology does not work or does not give a good reading. “Sometimes, the corneal marking is your fallback,” he said.

Tip 3: Consider the role of the posterior cornea

Cataract surgery leaders have recently reported on the importance of posterior cornea measurements, which can be done in several different ways. Dr. Findl and staff always perform corneal topography and tomography and use the latter to assess the posterior cornea versus anterior cornea. “The posterior cornea will contribute much less, but there are some odd eyes where it can be quite different [from the anterior cornea],” he said. In those cases, they will consider it in their calculations.

There are online calculators such as the Barrett Toric Calculator (available at ascrs.org) that account for posterior cornea measurements, Dr. Weinstock said.

Tip 4: Beware of too many measurements

“There’s always a tradeoff,” Dr. Findl said. “[If you measure more], you can also introduce noise, and that doesn’t necessarily make things better.” When it comes to the posterior cornea, Dr. Findl takes more of a qualitative look at data to decide what changes, if any, should be made for astigmatic correction. Surgeons also need to consider if certain measurements (beyond just the posterior cornea) seem out of place due to dry eye, an irregular cornea, or other factors.Advanced technology article summary

Tip 5: Let patients know that adjustments may take place

Even with the best technology, refractive enhancements or IOL exchanges may be needed, Dr. Findl said. If patients know ahead of time, they likely will be more open to the possibility.

Editors’ note: Dr. Findl has financial interests with Abbott Medical Optics (Abbott Park, Illinois) and Carl Zeiss Meditec. Dr. Lane has financial interests with Alcon, Bausch + Lomb (Bridgewater, New Jersey), and other ophthalmic companies. Dr. Weinstock has financial interests with Alcon, Bausch + Lomb, and LENSAR (Orlando, Florida).

Contact information

: oliver@findl.at
Lane: sslane@associatedeyecare.com
Weinstock: rjweinstock@yahoo.com

Related articles:

Report offers recommendations for handling adverse events in cataract surgery by Ellen Stodola EyeWorld Senior Staff Writer

Achieving best outcomes with cataract surgery in the post-vitrectomized eye by Liz Hillman EyeWorld Staff Writer

Review of Comparison of vitreous loss rates between manual phacoemulsification cataract surgery and femtosecond laser-assisted cataract surgery by David Patterson, MD, and the residents of the Mayo Clinic Department of Ophthalmology

Chop techniques guided by technological innovations by David Laber EyeWorld Staff Writer

Advanced technology sharpens astigmatic outcomes after cataract surgery Advanced technology sharpens astigmatic outcomes after cataract surgery
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