A New Generation of IOLs

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Cataract surgery is the most frequently performed operation around the globe. And because the world’s pop­ulation is increasing and aging, the demand for IOLs is rising. Continually more patients also ex­pect that the surgery will free them from glasses. To answer the call, IOL manufacturers have been rolling out a number of premium lenses that are now on the market for U.S. surgeons. 

“We’re in an incredibly exciting time in the re­fractive cataract space,” said Brian M. Shafer, MD, at Chester County Eye Care in Malvern, Pennsyl­vania. New monofocal, extended-depth-of-focus (EDOF), and multifocal offerings are available to patients who in the past had no possibility of spectacle independence following cataract surgery, he said.

This competition is good for patients, surgeons, and, ultimately, industry, said Michael Greenwood, MD, at Vance Thompson Vision in West Fargo, North Dakota. He added that it also creates challenges for ophthalmologists because when lens options increase, so too does the difficulty of knowing what’s best for each patient. “We all have our go-to fastball—the lenses we’re most comfortable with for one reason or another—but it’s our responsibility to be well-versed in the new IOL options and stay up to date on the nuances involving their use.”

Monofocal IOLs

Monofocal IOLs offer spherical correction for a single distance and are many ophthalmologists’ first choice because of their superior image clarity and minimal visual aberrations, said Kendall E. Donaldson, MD, MS, at the Bascom Palmer Eye Institute in Plantation, Florida. In addition, they’re ideal for patients with preexisting ocular comor­bidities, she said.

Tecnis Eyhance. Johnson & Johnson’s latest monofocal IOL acts like a monofocal-plus, said Dr. Shafer, in that it provides functional interme­diate vision and excellent distance visual acuity. But because it does drop off at the near range, the Eyhance does not meet the criteria to be con­sidered an EDOF or multifocal lens, he said.

“The benefit of the Eyhance lens is that it pro­vides intermediate vision without the glare or halos commonly found in EDOF and multifocal tech­nology,” said Dr. Shafer. Plus, he added, “The modulation transfer function—the amount of light that transfers through the lens—is such that patients can expect to see well even in low-light conditions.”

And because the lens’ defocus curve moves toward the intermediate range, said Dr. Donald­son, the surgeon can offset the eyes with a slight mini-monovision—correcting for distance in one eye and near in the other—to provide the likeli­hood of spectacle independence across the full range of vision. “The Eyhance has become my go-to lens,” she said. “Although approved as a mono­focal lens, I tell my patients that it’s a distance lens; however, I can get an extra diopter to a diopter and a quarter of intermediate vision with it—which is especially key because of how tied we now are to our smartphones.”

enVista. Like the Eyhance, Bausch + Lomb’s enVista IOL is a monofocal lens that may provide added depth of focus. What sets it apart from standard monofocal lenses is that the optic is aberra­tion-free, said Dr. Shafer. “This is very beneficial because the lack of asphericity allows for the spher­ical aberration of the cornea to provide for a little bit of added depth of focus. As a result, you can expect the defocus curve to push the patient closer toward acceptable vision in the intermediate range. This also makes the lens more forgiving when slightly decentered.”

Light Adjustable Lens. RxSight’s Light Adjust­able Lens (LAL) is a silicone, three-piece mono­focal IOL that’s filled with macromers, a photo­sensitive material that changes the lens’ shape and power in response to ultraviolet light. Because it’s the only lens on the U.S. market that’s fully adjust­able after cataract surgery, the LAL has completely disrupted lens technology, said Dr. Shafer. “Every other type of IOL moves in half diopters, but we can throw that out the window here. The light delivery device allows us to fine-tune down to quarter diopters, which allows for adjustability in ways we’ve never had avail­able to us before.”

This is especially helpful in patients whose preopera­tive calculations are difficult to measure or who have undergone previous laser vision correction, said Dr. Greenwood. “Because the surgeon has three opportunities to adjust the LAL before lock­ing it in, you can change your target for a patient who decides that maybe they do want a little bit more near vision after the fact.” As a result, patients can optimize their postoperative visual acuity and potentially avoid a corneal refractive procedure that might otherwise be needed to meet the patient’s expectations, he said. “The LAL is also nice because if you want to create a customized monovision for a patient who’s never had experience with that world, you can ease them in, almost to the point where they can’t really tell the difference.”

Caveat. Patient selection is key, though, said Dr. Shafer. “Highly irregular corneas, for example, may not adjust as predictably as those that are perfectly regular,” he said. “Nevertheless, you can still give patients who have retinal pathology the option for a premium experience and true customization.”

It’s also very important that surgeons implant the LAL in patients who are willing to protect their eyes with UV glasses for the full three weeks before the final adjustment period begins, said Dr. Greenwood. Although RxSight has recently updat­ed its lenses with technology that makes the LAL less reactive to ambient UV light, natural sunlight may still inadvertently polymer­ize the lens and lead to internal higher-order aberration, he said.

Clareon. Cataract surgeons should also be aware of Clare­on, Alcon’s new lens material for its monofocal line, said Dr. Shafer. “We’re all very familiar with the tried-and-true AcrySof platform, but we also know that its downside is the development of glistenings in the lens. While there’s debate about whether these glistenings are visually significant, they are measurable, and internal ray tracing shows us that they can result in the development of higher-order aberrations.”

Clareon is the response to these glistenings, said Dr. Greenwood. “In the surgeon’s hands, the new material is very similar to previous AcrySof IOLs—same optics, same haptic design,” he said, “just with better clarity and a new au­tomated injector system that allows the surgeon to gently deliver the IOL.” Although available only in Alcon’s monofocal line, the Clareon platform is expected to be phased into the company’s multifocal lens offerings in the near future, he said.

Extended-Depth-of-Focus IOLs

EDOF lenses extend the range of focus and augment intermediate and near vision via the creation of a single elongated focal point rather than sev­eral foci, as in multifocal lens technology. “Near vision with EDOF IOLs may not have the same clarity as their multifocal counterparts,” said Dr. Donaldson, “but they are especially appealing because of reduced aberrations and improved in­termediate vision without compromising distance visual acuity or introducing bothersome positive dysphotopsias, which can be associated with some multifocal lenses.” EDOF lenses are also more forgiving in patients with certain existing preoper­ative conditions, she added. For example, patients with a small epiretinal membrane or a history of LASIK with mild higher-order aberrations may not be candidates for multifocal lenses, but they might still be a fit for an EDOF lens, she said.

Tecnis Symfony. Johnson & Johnson’s EDOF offering, the Tecnis Symfony, utilizes a proprietary design to provide an intermedi­ate vision profile, said Dr. Greenwood. One scenario in which he frequently uses the Symfony lens is mixing and matching, where a patient receives an EDOF IOL in their dominant eye and a multifocal in the nondominant eye. “These patients are coming away with very good range of vision with distance, intermediate, and near,” he said.

Caveat. A limiting factor with the Symfony, said Dr. Shafer, is the risk of a distinct positive dysphotopsia. “The lens’ classic visual artifact is a starburst phenomenon. But in my experience, even though patients tend to notice it, they tolerate the dysphotopsia well and aren’t typically bothered by it.” Nonetheless, you should counsel candidates about this ahead of time, he said.

Vivity. Alcon’s Vivity utilizes a proprietary technology to offer a non­diffractive option for extended range of vision. “What you can see when you first look at the Vivity is a central bump,” said Dr. Shafer. “Rather than splitting light, this bump condenses all of the light rays into an elongated pattern for favorable intermediate vision.” It’s very much a disruptive technology, he added, because it allows the sur­geon to implant an EDOF lens in eyes that would not benefit or not be suitable for diffractive tech­nology. As a result, patients who have mild macu­lar pathologies such as an epiretinal membrane or mild corneal pathologies such as prior LASIK or mild guttata from Fuchs dystrophy can experience the benefit of an EDOF IOL, he said.

Based on Dr. Greenwood’s experi­ence, both patients with healthy eyes and those who aren’t good candidates for multifocal lenses do well with the Vivity IOL, especially for distance and intermediate. “One of the terms that’s been thrown around is ‘dashboard to distance,’ and our patients can largely achieve that using the Vivity lens with minimal dysphotopsia or glare and halo,” said Dr. Greenwood. “Even in eyes with some pathology, the results are positive. It just requires a little more chair time to explain to the patient how their near or intermediate vision might be a little bit limited.”

Caveat. One important caveat with the Vivity lens is that the defocus curve is somewhat pupil dependent, added Dr. Shafer. Therefore, patients with larger pupils may not come away with as much near vision as those with smaller pupils. So it’s important to consider this preoperatively for Vivity patients, he said.

Give near vision a boost. All in all, said Dr. Shafer, both the Symfony and Vivity IOLs offer patients the ability to see well at both distance and intermediate out of the box. But to give their patients’ near vision a boost, cataract surgeons may want to consider a bit of mini-monovision with these lenses to expand the defocus curve to a fuller range, he said.

Multifocal IOLs

Multifocal IOLs utilize diffractive optics to create three distinct focal points. As a result, they allow for the greatest range of near, intermediate, and distance vision, said Dr. Greenwood. In the past, factors that have limited more widespread use of these lenses included patient dissatisfaction due to dysphotopsias and the experience of discrete optical zones rather than a smooth transition be­tween focal lengths, he said. He added that today’s newest multifocals are “light-years” ahead of what existed even five years ago and may be considered an optimal IOL for many patients.

PanOptix. Alcon’s latest multifocal option, the PanOptix IOL, offers all three ranges of vision with minimal drop-off in between, said Dr. Greenwood, so it provides significant continua­tion of vision. “And what’s particularly nice is that we can place the PanOptix in both eyes, whereas historically we’d mix and match lenses to achieve a good range of vision,” he said. “With a single lens type, patients’ neural adaptation quickens and they’re able to adjust to their new vision in much less time than with mix and match.” Because both eyes are cooperating and sending the brain the same signals, this decreases the risk for both posi­tive and negative dysphotopsias, he added.

Dr. Greenwood has had especially good success using the PanOptix lens in patients with relatively healthy eyes—meaning no corneal pathology, no retinal pathology, no glaucoma, and normal topographies. “But the IOL also performs well in patients with previous LASIK or photorefractive keratectomy procedures,” he said. “My colleagues and I are working on a research study right now to quantify that a little bit more, but anecdotally, it’s safe to use these lenses in patients who have had previous refractive surgery, as long as the cornea and the higher-order aberra­tions are within normal limits.”

Tecnis Synergy. Johnson & Johnson’s Tecnis Synergy IOL is a hybrid lens—part trifocal, part EDOF. Taken together, both the Synergy and the PanOptix perform well in healthy eyes, said Dr. Donaldson, but there are nuances that surgeons will better understand with experience. “For example, I’ve found that the Synergy lens provides significantly stronger near vision than the PanOptix so far. In my higher myopic pa­tients who want a multifocal lens, I’m using more Synergy lenses, as opposed to just the regular emmetropic or hyperopic patient who does well with the PanOptix.”

Patient selection. And because both the PanOptix and Synergy lenses utilize diffractive technology, it’s critically important to focus on patient selection, said Dr. Shafer. “Patients with high corneal higher-order aberrations may not do well with these multifocal lenses and may experience increased photic phenomena or photopsia such as glare and halos,” he said. “And while more than 90% of my PanOptix patients are satisfied with their lens and would have it again, many, if not most, do notice these dysphotopsias but aren’t bothered by them. The same appears to be true with the Synergy lens.”

Ophthalmologists should also be on the lookout for any impending macu­lar pathology, said Dr. Shafer. Like all diffractive technology, these multifocal lenses split light to achieve the entire range of vision. So, it’s important to avoid their placement in a patient with true macular pathology—some drusen or an epiretinal membrane—since the photoreceptors won’t receive the necessary light.

Patient age might also come into play, added Dr. Shafer. The PanOptix’s AcrySof material may not be quite as durable as the Tecnis material from which the Synergy is made, so the surgeon should think twice when implanting the PanOptix in a younger patient. Once the PanOptix is available on the Clareon platform, this conversation may change, he said.

Final Thoughts

Whatever IOL lens you choose—monofocal, EDOF, or multifocal—be aware that more are on the way. Ophthalmologists in Europe and Asia have many new-technology lenses available to them, and U.S. surgeons can expect their options to continue to grow and can expect more companies to enter the marketplace following FDA trials, said Dr. Shafer. “It’s really exciting that we have the ability to use all of these lenses to match patients, their eyes, and lens technology,” he said. “This is the best time to be in the refractive cataract field, and it will only get better from here.”

Meet the Experts

Kendall E. Donaldson, MD, MS Professor of clinical ophthalmolo­gy and medical director, Bascom Palmer Eye Institute in Plantation, Fla. Relevant financial disclosures: Alcon: C,L; Bausch + Lomb: C; Carl Zeiss Med­itec: C; Johnson & Johnson: C.

Michael Greenwood, MD Private practice, Vance Thompson Vision in West Fargo, N.D., and clinical instructor of surgery, University of North Dakota in Grand Forks, N.D. Relevant financial disclosures: Alcon: L; John­son & Johnson: L.

Boris Malyugin, MD, PhD Profes­sor of ophthalmology and deputy director general at the S. Fyodorov Eye Microsurgery Federal State Institution in Moscow. Relevant financial disclosures: Alcon: L; Carl Zeiss Med­itec: C.

Brian M. Shafer, MD Private prac­tice, Chester County Eye Care in Malvern, Penn. Relevant financial disclosures: Alcon: C.

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