Published in Refractive Surgery

Approaches to Astigmatism Management with the Femtosecond Laser

This is editorially independent content
6 min read
Drs. Gupta and Wörtz review methods available to ophthalmologists for managing astigmatism using a femtosecond laser.
In this installment of Interventional Mindset, Gary Wörtz, MD, speaks with Preeya K. Gupta, MD, about methods for managing astigmatism, including using a femtosecond laser.
Astigmatism has always been a bit of a mysterious condition to treat, Dr. Wörtz begins: when he first started as an ophthalmology resident, he didn’t think about correcting astigmatism until a patient had about a diopter or more.
However, with time and the more widespread implementation of the femtosecond laser, he realized that there was now a new tool and opportunity to treat patients with lower-level astigmatism who wouldn’t necessarily benefit from a toric lens.
Interventional Mindset is an educational series that gives eye physicians the needed knowledge, edge, and confidence in mastering new technology to grow their practices and provide the highest level of patient care. Our focus is to reduce frustrations associated with adopting new technology by building confidence in your skills to drive transformation.
Browse through our videos on a variety of topics within cataract and refractive surgery, glaucoma, and ocular surface disease to learn practical insights into adopting a variety of new surgical techniques and technology.

Using the femtosecond laser to treat lower-level astigmatism

Astigmatism management is rarely straightforward, notes Dr. Gupta. Higher levels of astigmatism will clearly benefit from toric IOLs, but lower levels of astigmatism are still a valuable area of focus for practitioners.
In a paper co-authored by Dr. Gupta and Wörtz, they showed that managing low levels of astigmatism (less than a diopter) leads to more patients achieving 20/20 uncorrected visual acuity. Intervening earlier in astigmatic patients and using a femtosecond laser caused almost a 200% increase in 20/20 uncorrected patients and over a 350% increase in uncorrected 20/25 visual acuity at the end of treatment.
Dr. Wörtz mentioned that prior to the study, he observed that patients undergoing cataract surgery with a monofocal lens and femto arcuate incisions were getting very close to plano sphere after undergoing the femtosecond laser procedure. But it wasn’t until he looked at the data from the study that this hunch was confirmed; treating lower levels of astigmatism, and having a plan for those patients, gives them the refractive outcome they are looking for.

Identifying tools for treating lower-level astigmatism

One of the key issues clinicians encounter when treating astigmatism is deciding which treatment modality to choose. There are so many potential approaches for treating astigmatism that it’s almost a paradox of choice.
Dr. Gupta broke down her process for treating an astigmatic patient that helps combat this problem. Before even walking into a patient’s room, she looks at their topography and biometry using the Zeiss IOL Master 700. Then she looks at the patient’s magnitude and axis of astigmatism to gauge what tools may be needed to full address the astigmatism at the time of cataract surgery.
For patients with higher levels of astigmatism, she leans towards using a toric lens, but for lower levels, she often uses the femtosecond laser to create arcuate incisions. During the procedure, optical coherence tomography (OCT) is used to place the incisions, allowing for, in Dr. Gupta’s opinion and experience, a more precise shape and depth compared to manual limbal relaxing incisions.
From a corneal perspective, a key thing to look for is if the patient has any corneal irregularities, such as Fuchs dystrophy, pterygium, anterior basement membrane dystrophy (ABMD), or anything that could contribute to irregular astigmatism. For any patient with a normal cornea and low levels of astigmatism, Dr. Gupta’s process from there is to use a femtosecond laser.

Using the Wörtz-Gupta Formula for femtosecond laser procedures

Dr. Gupta and Dr. Wörtz put together the Wörtz-Gupta Formula, which is a femtosecond laser arcuate incision formula. It is freely available at www.LRIcalc.com and requires only three input variables—patient age, location of steep axis, and magnitude of astigmatism. This formula is the first to be specifically designed for femtosecond laser-assisted arcuate incisions.
Prior manual limbal relaxing incision formulas have been attempted to be adjusted but not validated with femtosecond laser usage.  The formula has only been studied for correction of corneal astigmatism <1.25D using a femtosecond laser at a 9.0mm optical zone and 80% depth, opened manually at the time of cataract surgery.
A unique feature of this calculator is that the incision is held constant (always at 0 or 180), so it was designed to show the procedure from a temporal approach. This calculator helps to simplify the complexities of determining the most effective arc length and also validates the importance of treating lower levels of astigmatism. Astigmatism management, Dr. Gupta argues, is something that should be considered with every patient. The capabilities of the femtosecond laser support this attention.

Conclusion

Using the femtosecond laser to treat patients with lower-level astigmatism shows the value of having an interventional mindset as a surgeon. By proactively identifying astigmatism and treating it at the time of cataract surgery, patients will have improved uncorrected acuity.
Adopting the femtosecond laser for arcuates and implementing the Wortz-Gupta formula has simplified our abilities to provide that excellent uncorrected vision that patients desire. So if you haven’t checked out www.LRIcalc.com, try it on your next few cases.
Ultimately, this is the focus and goal of the Interventional Mindset series: to disseminate knowledge, experience, and resources to fellow surgeons to get the best possible patient outcomes.
Preeya K. Gupta, MD
About Preeya K. Gupta, MD

Dr. Gupta earned her medical degree at Northwestern University’s Feinberg School of Medicine in Chicago, and graduated with Alpha Omega Alpha honors. She fulfilled her residency in ophthalmology at Duke University Eye Center in Durham, North Carolina, where she earned the K. Alexander Dastgheib Surgical Excellence Award, and then completed a fellowship in Cornea and Refractive Surgery at Minnesota Eye Consultants in Minneapolis. She served on the faculty at Duke University Eye Center in Durham, North Carolina as a Tenured Associate Professor of Ophthalmology from 2011-2021.

Dr. Gupta has authored many articles in the peer-reviewed literature and serves as an invited reviewer to journals such as Ophthalmology, American Journal of Ophthalmology, and Journal of Refractive Surgery. She has also written several book chapters about corneal disease and ophthalmic surgery, as well as served as an editor of the well-known series, Curbside Consultation in Cataract Surgery. She also holds several editorial board positions.

Dr. Gupta serves as an elected member of the American Society of Cataract and Refractive Surgery (ASCRS) Refractive Surgery clinical committee, and is also is the Past-President of the Vanguard Ophthalmology Society. She gives presentations both nationally and internationally, and has been awarded the National Millennial Eye Outstanding Female in Ophthalmology Award, American Academy of Ophthalmology (AAO) Achievement Award, and selected to the Ophthalmologist Power List.

Preeya K. Gupta, MD
Gary Wörtz, MD
About Gary Wörtz, MD

Gary Wörtz, MD is a board-certified ophthalmologist from Lexington, KY specializing in cataract and refractive surgery.

Since completing his training in 2008, Dr. Wörtz has successfully performed thousands of cataract and laser procedures. He currently practices in Lexington at Commonwealth Eye Surgery. Dr. Wörtz became one of the first surgeons in Kentucky to perform laser refractive cataract surgery. He utilizes the latest technology both in and out of the operating room to help restore vision for cataract patients.

Dr. Wörtz enjoys innovation and teaching his techniques to others around the country. He has been a consulting speaker for Alcon, AMO, Bio-Tissue, TearLab, Carl Zeiss Meditech and Dialogue Medical. He has also been a principal investigator in multiple FDA pharmaceutical trials in the ophthalmic sector. He has given numerous lectures at both the American Academy of Ophthalmology and the American Society of Cataract and Refractive Surgeons annual meetings. He is also a frequent contributor to many trade journals such Cataract and Refractive Surgery Today, MillennialEye, Ophthalmology Times, and EyeWorld, and was recently named to the editorial board of Ocular Surgery News.


Gary Wörtz, MD
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