Advanced IOLs provide array of options for cataract surgeons

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Reviewed by J. Morgan Micheletti, MD

With the plethora of advanced technology IOLs available, it is incumbent upon the cataract surgeon to assess the patient and determine what is the most appropriate IOL for the given patient, according to J. Morgan Micheletti, MD, cataract, refractive, and complex anterior segment surgeon, director of Clinical Research and Technology, Berkeley Eye Center, Houston, Texas, speaking at the Toronto Cataract Course 2023 in Toronto.

“As we move through all of this IOL technology, the main takeaway from this talk today is that there is no one perfect IOL,” Micheletti said. “I cannot tell you one particular lens will work in every patient. You’ll notice the name of the talk is ‘Marrying an IOL to an Eye,’ a concept I first heard Dr. Brian Shafer talk about, and that is what we are looking to do. That is really your job as the surgeon: to find that match for that patient.”

One of the challenges of comparing visual outcomes with IOLs is that they have been measured using different techniques and at different distances or lighting conditions, said Dr. Micheletti.

“The issue is a lot of them [defocus curves[ are not comparable because they have been measured or may have been measured with Snellen or with ETDRS [early Treatment Diabetic Retinopathy Study], or may have been measured at 2 metres, or may have been measured at 4 metres, so it is really hard to do apples-to-apples comparisons between different studies,” he said. “It is important that if we can standardize how we all measure defocus curves, then maybe we can draw more conclusions and be able to compare defocus curves from different studies.”

Advanced technology IOLs involve both diffractive and refractive technologies, pointed out Dr. Micheletti.

“When it comes to diffractive technology, we’re exploiting the wave-particle duality of light,” Micheletti explained. “We are modifying the wave function to induce constructive and destructive interference. You can then shift and converge the wavefronts to various focal points. And that’s how many of our diffractive IOLs work.”

Currently, 3 IOLs are available in the US that meet the American National Standards Institute criteria to be classified as an extend- ed depth of focus [EDOF] IOL. Those 4 criteria are: distance-corrected intermediate visual acuity [DCIVA] that is superior to a monofocal IOL, depth of focus that is ≥ 0.5 D greater than a monofocal at 0.2 logMAR on a defocus curve, achieving DCIVA of 0.2 logMAR or better in 50% of eyes, and best-corrected distance visual acuity that is non-inferior to a monofocal at distance. These EDOF IOLs include the Symfony, Vivity, and Aphthera lenses, noted Micheletti, with the first FDA-approved EDOF IOL being the Tecnis Symfony IOL.

In terms of who would be a candidate for an EDOF or multifocal IOL, various factors influence the choice, Micheletti explained.

“Who might be a candidate?” Micheletti asked. “Well, the first thing I’m going to say is personality [of the patients]. Know your patients, spend time with them, and understand what their goals and aspirations are. And then beware of the low moderate myope.”

Advanced technology IOLs, including the light adjustable lens [LAL], can be implanted in almost all patients, but patients that Micheletti most commonly excludes as candidates for advanced technology IOLs are those with macular degeneration.

As EDOF IOLs provide more range than monofocal IOLs and create fewer dysphotopsias than multifocal lenses, they are a good fit for patients who are night drivers, such as truck drivers and pilots, according to Dr. Micheletti, adding EDOF IOLs are also a good fit for patients with mild ocular surface issues, mild or moderate glaucoma, and mild cases of epiretinal membrane.

Clinicians can consider “blending”, that is using an EDOF lens in the dominant eye of the patient and a multifocal IOL in the patient’s non-dominant eye, said Dr. Micheletti. Other possible combinations of IOLs could include blending with a monofocal lens or an LAL.

Some IOLs, such as the Tecnis Symfony OptiBlue IOL, contain achromatic technology that corrects chromatic aberration, resulting in a sharper focus of light and enhanced image contrast in both the day and night, noted Micheletti.

The Tecnis Symfony OptiBlue IOL im- proves upon the Tecnis Symfony IOL by decreasing light scatter and halo intensity, Micheletti added.

Another EDOF IOL, the Clareon Vivity IOL, leverages non-diffractive technology that stretches the wavefront, creating a continuous extended focal range, and shifting the wavefront to use all available light energy, explained Micheletti. The non-diffractive nature of the Vivity IOL allows for a reduction in dysphotopsias similar to those of a monofocal IOL.

The IC-8 Apthera IOL is a hydrophobic lens that delivers continuous range of vision, according to Micheletti.

“With more continuous range of vision technologies, a lot of times we don’t have to have that discussion with patients who are looking for a full range of vision,” he said.

Continuous range of vision IOLs available in the US include the only trifocal IOL, the Alcon PanOptix, and the Tecnis Synergy, the latter of which is a blend of EDOF and bifocal IOL technology, said Dr. Micheletti.

LALs are silicone IOLs that allow for pa- tient-driven, customized titration of vision, but they represent a time commitment on the part of patients and clinicians as multiple visits for adjustments/lock in are needed, said Micheletti.

“I really like this (LALs) for post-refractive patients so long as they’re willing
to complete all the extra visits because it requires more visits compared to other IOLs,” said Dr. Micheletti, noting light adjustments can be performed 3 to 5 times including the 2 lock-ins.

Finally, cataract surgeons should be mindful of potential visual interference from the vitreous and any possible need for a referral to retinal colleagues to perform a vitrectomy, said Micheletti.

J. Morgan Micheletti, MD
P: 713-526-1600
Micheletti is a consultant for Alcon, Allegan, Avellino, Bausch & Lomb, BVI, Centricity, Diamatrix, Glaukos, J&J, New World Medical, RxSight, STAAR, Tarsus, Visus Therapeutics, and Zeiss. He is a speaker for Alcon, Glaukos, J&J, Lenstec, RxSight, and STAAR. He receives research grants from Alcon and J&J. He holds a patent with Diamatrix.