Dialing in precision: Astigmatism management with arcuate incisions

Even small amounts of astigmatism can affect visual clarity, much like a radio that is slightly off-station. (Image credit: AdobeStock/NicoElNino)

One compelling advantage of robotic laser cataract surgery is the level of precision it brings to astigmatism management with arcuate incisions. Unlike the variability with manual limbal relaxing incisions, robotic laser arcuate incisions can be placed precisely at an exact depth, arc length, and optical zone.

More than half of individuals (62.2%) have astigmatism ranging from 0.00 to 1.00 D.¹ Research shows that even a small amount of residual astigmatism after cataract surgery can significantly impact patients’ visual acuity, potentially leading to correction with glasses or contact lenses as well as decreased quality of life and postoperative dissatisfaction.^2,3 For patients opting for premium IOLs, meticulous astigmatism management is therefore essential.

IntelliAxis software on a robotic cataract laser system (ALLY; LENSAR, Inc) compensates for cyclorotation, ensuring that the incisions are aligned with an accuracy of within 1 degree of the intended axis. This reduces the chance of residual astigmatism.

Another tool to add precision to astigmatism correction is the use of a nomogram to optimize the size and placement of the arcuate incisions. Although formulas exist for this purpose, most were created for manual arcuate incisions. If used with a femtosecond laser, estimated adjustments are required.

READ: Robotic precision: Elevating the state of laser cataract surgery, by Vance Thompson, MD

Alternatively, the Wörtz-Gupta formula is designed for use with laser arcuate incisions. Compared with patients who underwent standard cataract surgery, those who received laser arcuate incisions for the treatment of 0.25 and 1.00 D of astigmatism based on this formula were 1.8 times more likely to achieve 20/20 vision and 3.54 times more likely to achieve 20/25 vision or better without correction.⁴ The formula is available online at LRIcalc.com and integrated with the Veracity surgical system (Carl Zeiss Meditec AG).

MORE: AI applications in cataract surgery: A surgeon’s perspective, by Arjan Hura, MD

Many surgeons underestimate the impact of residual astigmatism on visual quality until they start actively treating it. An analogy is tuning an old radio: If you’re slightly off the station, you may still hear the song, but it’s not crisp. Correcting even small amounts of astigmatism ensures patients enjoy crystal-clear vision instead of settling for minor blurriness.

With a robotic cataract laser system and the Wörtz-Gupta formula, ophthalmologists have the tools to fine-tune their surgical approach, improve postoperative outcomes, and elevate laser cataract surgery to a new level of accuracy and efficiency.

Gary Wörtz, MD

E: 2020md@gmail.com

Wörtz practices at Commonwealth Eye Surgery in Lexington, Kentucky. He is a cofounder of Arcuate Innovations and is a consultant to Carl Zeiss Meditec AG and LENSAR, Inc.

References

1. Astigmatism correction. East Valley Ophthalmology. Accessed February 14, 2025. https://doctor-hill.com/mesa-eye-doctors/specialists/cataract-surgery/astigmatism-correction

2. Schallhorn SC, Hettinger KA, Pelouskova M, et al. Effect of residual astigmatism on uncorrected visual acuity and patient satisfaction in pseudophakic patients. J Cataract Refract Surg. 2021;47(8):991-998. doi:10.1097/j.jcrs.0000000000000560

3. Wu C. Control of astigmatism in cataract patients. American Academy of Ophthalmology. May 7, 2008. Accessed February 14, 2025. https://www.aao.org/education/current-insight/control-of-astigmatism-in-cataract-patients

4. Wörtz G, Gupta PK, Goernert P, et al. Outcomes of femtosecond laser arcuate incisions in the treatment of low corneal astigmatism. Clin Ophthalmol. 2020;14:2229-2236. doi:10.2147/OPTH.S264370