by Michelle Dalton EyeWorld Contributing Writer
Still not available in the U.S., European surgeons are beginning to prefer the technology over other premium lenses
When multifocal lenses were first introduced, they were heralded as a means of providing both near and distance vision improvements for patients undergoing cataract surgery. These IOLs feature two main foci, but patients continually demanded better intermediate vision. In today’s world, one could argue intermediate vision is even more crucial than near for performing daily tasks such as using a computer, tablet, or smartphone.
Trifocal IOLs combine two diffractive profiles to improve vision across all spectrums, and published reports indicate high levels of both spectacle freedom and patient satisfaction. The technology has yet to be introduced in the U.S., but those familiar with the lenses are embracing the technology and think it offers patients the best potential visual outcome. “With trifocal IOLs, distance visual acuity (VA) is at least as good as a multifocal, intermediate VA is significantly better, and reading vision is slightly worse than a multifocal’s reading vision,” said Arthur Cummings, MBChB, Wellington Eye Clinic, Dublin, Ireland. In Ireland, three trifocal lenses are approved and available: AT LISA (Carl Zeiss Meditec, Jena, Germany), FineVision (PhysIOL, Liege, Belgium), and PanOptix (Alcon, Fort Worth, Texas). For A. John Kanellopoulos, MD, LaserVision.gr Institute, Athens, Greece, and clinical professor of ophthalmology, New York University Medical College, New York, the primary driving force behind these lenses has been intermediate vision and quality of vision in lieu of contrast sensitivity in the refractive cataract patient. “In the U.S., there’s been a step back from multifocal lenses and working with extended depth of focus. In Europe, though, there’s a very large following with trifocal lenses,” he said. Three technologies have been predominant in Europe: the FineVision, the AT LISA, and the PanOptix lens. In Belgium, in addition to those three lenses, the Alsafit (Alsanza, Pfullingen, Germany) and Acriva Reviol trifocal (VSY Biotechnology, Amsterdam, Netherlands) are also available, said Erik Mertens, MD, Medipolis, Antwerp, Belgium. The FineVision and AT LISA are also available in toric versions, and the PanOptix is expected to have a toric version shortly. Additionally, the second order light diffraction “is effectively utilized in trifocal lenses to provide intermediate vision, thus beside gaining an additional focus at the intermediate zone, there is less loss of defocused light and less side effects such as glare and reduced contrast sensitivity,” said Ehud Assia, MD, director, Department of Ophthalmology, and medical director, Meir Medical Center, Tel Aviv, Israel. “As more manufacturers are entering this field, the intermediate vision is definitely the most important feature of these lenses.
The loss of light is reduced more and more by using it in different orders. Still, there are some issues with contrast sensitivity and halos, but a lot less than with bifocal or multifocal IOLs. Well-informed patients know that they will be bothered for the first month, but this improves due to brain adaption up to 6 months after surgery,” Dr. Mertens said. Comparing trifocal lenses Patients seem to prefer trifocal lenses more so than multifocal, these physicians said, and trifocals compare favorably to other enhanced vision lenses as well. For instance, extended depth of focus lenses “are a completely different aspect for refractive cataract surgery, as they offer optimal distance acuity and contrast sensitivity and some improved intermediate VA,” Dr. Kanellopoulos said. “Trifocal lenses may offer complete independence from spectacles at both distance and intermediate.
Our 5-year experience in Europe is very positive. I can see making these lenses a mainstay surgical treatment globally and in the U.S.” Trifocals outperform accommodative, extended depth of focus, multifocal IOLs in general visual performance and regarding dysphotopsia, Dr. Cummings said. The lenses produce fewer higher order aberrations such as halo, Dr. Mertens added. Dr. Assia recently reviewed clinical results using PhysIOL trifocal IOLs and found that “90% had 6/9 uncorrected distance VA or better, 85% had 6/9 uncorrected intermediate VA, and 95% had uncorrected near VA of J2 or better,” he said. Toric trifocals showed similar results in astigmatic patients, Dr. Assia said. In comparison, in patients implanted with the Tecnis Symfony extended depth of focus lenses (Abbott Medical Optics, Abbott Park, Illinois), uncorrected distance VA was 6/9 in 84% of patients, uncorrected intermediate VA was 6/9 in 86%, “but uncorrected near VA of J2 and better was recorded in 44% only,” he said.
The better visual outcomes and similar side effects are propelling patient preference, Dr. Assia said. Dr. Kanellopoulos said he’d been “discouraged initially” with multifocal lenses because of the contrast sensitivity issue in high scotopic and mesopic conditions and the inability to function with intermediate vision. But he’s a firm advocate for trifocal lenses. “They appear to be an extremely good solution for a significant number of patients who require or would benefit from spectacle independence due to lifestyle or preference,” Dr. Kanellopoulos said.
Patient selection pearls Patient selection was deemed a crucial aspect when considering multifocal or accommodative lenses, but those kinds of strict criteria “usually applies to technologies that are not intended for mass adoption,” Dr. Kanellopoulos said. “In my hands, trifocal lenses are a product that could be offered to almost every patient with minimal disadvantages.” Dr. Mertens recommends surgeons apply the same caution in a potential trifocal patient as they would a multifocal patient. “This includes a thorough anamnesis with the lifestyle of the patient, determining his/her expectations and motivation—all of these are still key to success,” he said. As with any refractive cataract patient, he also advises checking for dry eye or corneal issues.
Treating the ocular surface before surgery is necessary regardless of the type of lens, but may be even more important with enhanced technologies. “Are there retinal problems such as drusen or diabetes? In the latter case, this is a relative contraindication and should be discussed in depth with the patient,” he said. “The higher the patient satisfaction, the better ambassadors they’ll be for your practice.” For Dr. Assia, patient selection, indications, and contraindications for trifocals are generally similar to bifocals, however, “since clinical results are superior, the selection criteria for trifocals is slightly more liberal than bifocal lenses.” Dr. Cummings will “routinely” perform a multifocal contact lens trial on potential candidates, and “if patients like the contact lens trial, I am confident that they will like the trifocal IOL—especially if they have stated that their intermediate vision is much more important than their near vision.”
From a surgical standpoint, he recommends surgeons ensure that pupils are mobile and “not tonic and miotic.” While these lenses are still in their infancy, they seem to be on the verge of overcoming most patient complaints with other high technology lenses. “I think the future will surprise most clinicians in the trifocals’ ease of use and their potential advantages in enhancing and transforming cataract surgery into a supreme refractive surgical procedure with superior outcomes,” Dr. Cummings said. Editors’ note: Dr. Cummings has financial interests with Alcon. Dr. Mertens has financial interests with PhysIOL. Drs. Assia and Kanellopoulos have no financial interests related to their comments.