March 2015

 

COVER FEATURE

 

Refractive options

Multifocal IOLs


by Lauren Lipuma EyeWorld Staff Writer

 
   
ASCRS Clinical Survey

According to the 2014 ASCRS Clinical Survey, presbyopia-correcting lenses make up less than 10% of cataract surgeons annual volume. Source: ASCRS

Tecnis Symfony lens Tecnis Symfony lens Source: Abbott Medical Optics

With new multifocal IOL technology poised to enter the U.S. market, experienced surgeons discuss best practices for implantation

Multifocal IOLs have the potential to give patients spectacle independence after cataract surgery, but the difficulty in adapting to multifocality makes the lenses a good surgical option for a small percentage of patients. Multifocality is almost like a learned behaviortheres an adjustment phase that patients have to go through, said Robert Weinstock, MD, The Eye Institute of West Florida, Largo, Fla. Even with that, there are some patients who cannot get used to it and have some debilitating glare at night or an overall decreased quality of vision. New IOL technology poised to enter the U.S. market this year and new implantation techniques, however, will expand the multifocal options available to patients, offering the potential of increased range of vision, fewer unwanted visual effects, and astigmatism management options. With these new technologies and methods, surgeons may be able to offer multifocal IOLs to a wider array of patients. Dr. Weinstock, Douglas Koch, MD, professor and the Allen, Mosbacher, and Law chair in ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, and Bonnie An Henderson, MD, partner at Ophthalmic Consultants of Boston and clinical professor of ophthalmology at Tufts University School of Medicine, Boston, discussed the best practices for multifocal IOL implantation, techniques for mixing and matching multifocal and monofocal IOLs, and the new lens technologies that they are most excited about.

Who are the best candidates?

The physicians agreed that multifocal IOL candidates should have healthy eyes free of sight-threatening pathology, such as corneal scars or irregularities, significant dry eye, or macular pathology. Any type of epiretinal membrane, significant macular degeneration, or moderate end-stage glaucoma makes someone a poor candidate for a multifocal IOL, Dr. Weinstock said.

Because some patients with healthy retinas may go on to develop retinal pathology following surgery, it is vital to assess risk for retinal disease preoperatively, he added. Take a family history and look for risk factors such as diabetes and smoking, he said. Personality is another major factor in determining who is a good candidate for a multifocal IOL. According to Dr. Weinstock, the best candidates are those who have dense cataracts and have not been bothered by them. That lets you know that they have somewhat of an easygoing personalitythe fact that they havent rushed into cataract surgery, he said. In addition, a dense cataract causes a lot of glare at night, so these patients are already used to glare. If its not bothering them that much, theres a good chance that the glare from the multifocal wont bother them. Although surgeons have historically avoided implanting multifocal IOLs in type A personalities, do not exclude these patients as candidates, Dr. Henderson saidthey might have the most realistic expectations. I find that those type A patients have already done their homework and read about the difficulties of multifocal IOLs, she said. They understand the limitations but are willing to accept them in return for less spectacle dependence.

Astigmatism management

Another important criterion for multifocal IOL implantation is that the patient has manageable astigmatism that requires no treatment or can be treated reasonably with limbal relaxing incisions (LRIs) or other corneal incisions, Dr. Koch said. Addressing the astigmatism upfront is critical, Dr. Weinstock said. Its a process of preop, intraop, and even postop management. Astigmatism management starts with good topography and refractions preoperatively, he said. Measure multiple topographies on different devices to ensure that its regular astigmatism and that the measurements are repeatable from device to device. Some residual astigmatism is often tolerated with monofocal IOLs, Dr. Henderson said, but with multifocal IOLs, even small amounts can lead to poor vision and patient dissatisfaction. Her goal is to leave the patient with less than 0.5 D of residual astigmatism by operating on the steep axis or making LRIs or laser corneal incisions.

New lens options

The first toric multifocal IOLs will likely enter the U.S. market this year, allowing physicians to loosen the astigmatism restrictions and offer the technology to a whole new groups of patients.

Im eagerly awaiting the new multifocal designs that are coming out, Dr. Koch said. I think that the toric multifocal would be a wonderful advance, and Im looking forward to recently approved lower- add multifocal IOLs from AMO [Abbott Medical Optics, Abbott Park, Ill.]. A toric version of the AcrySof IQ ReSTOR multifocal IOL (Alcon, Fort Worth, Texas) will be available to U.S. physicians this year, as well as a lower add version of the lens (the ReSTOR +2.5 D), which will give patients sharper distance vision. In addition to toric and low add versions of existing multifocals, Drs. Koch and Weinstock are looking forward to the approval of the TECNIS Symfony extended range of vision lens (AMO) in the U.S. The Symfonys diffractive echelette design elongates the focal point, giving the wearer a continuous, full range of vision, with incidences of glare and halos comparable to a monofocal IOL. I think thats going to be one of the most optimal options were going to have going forward for our patients, Dr. Koch said. The Symfonys advanced optical system might be a tipping point in reducing unwanted side effects associated with multifocals, Dr. Weinstock said, which could lead to implantation in a larger percentage of patients.

Mix and match lenses

Multifocal IOL article summary Bilateral implantation is the most tried and true way of using a multifocal lens, Dr. Weinstock said, allowing the brain to receive similar images and facilitating neuroadaptation, but some surgeons have had success mixing and matching multifocal and monofocal IOLs. Dr. Koch will sometimes operate on the non-dominant eye first and implant a multifocal IOL. If they are pretty satisfied with the near vision but bothered by the halos, I might do a monofocal in the fellow eye, he said. For a seasoned refractive cataract surgeon, a similar option would be to put a monofocal or Crystalens accommodating IOL (Bausch + Lomb, B+L, Bridgewater, N.J.) in the dominant eye to give the patient crisp, high-resolution vision, and then place a multifocal IOL in the non-dominant eye, Dr. Weinstock said. Although there has been success with this technique, Dr. Weinstock said, he sees it as a niche procedure rather than a mainstream one. Its a little bit more work to start mixing and matchingit takes more time and energy, he said. There have been some studies that show its beneficial, but in my opinion, its going to be a niche methodology. Patients are often happier with their uncorrected near vision when both eyes are implanted with multifocal IOLs, Dr. Henderson said. If patients only have one eye implanted, usually that eye allows them to have some functional near vision for short-term vision such as reading the cell phone or looking at a price tag. However, without bilateral implantation, some patients may not feel that their uncorrected near vision is sufficient for longer-term reading.

The benefit of having one multifocal IOL and one distance corrected monofocal IOL is that the patient truly understands the benefits of the multifocal IOL and is usually happy to have at least one eye that can read without glasses. Dr. Koch thinks that adoption of the mix and match technique will depend on the lenses available. I think as our options expand, it will be tempting to do more mixing and matching, but well have to see, he said. For example, when a lens like the Symfony comes out, which gives distance and intermediate and some near, one could implant that in the dominant eye, and for the non-dominant eye, one could decide whether or not to go for more near vision with a multifocal or perhaps more safely elect micro-monovision with the Symfony.

Future of multifocals

Multifocal IOLsand presbyopia- correcting lenses in generalmake up less than 10% of cataract surgeons annual volume, according to the 2014 ASCRS Clinical Survey. But if these new technologies can offer patients better visual outcomes and fewer unwanted effects, surgeons will gain more confidence and use them more often, Dr. Weinstock said. The FDA focuses on safety and the efficacy, but in the real world its about the outcomes and the patient happiness, he said. Ultimately the patients and doctors decide whether or not the technology is prime time or whether its something that is not good enough to be in patients eyes. To me, the ultimate goal is to find a solution that will enable us to get rid of multifocals, Dr. Koch said. Theyre a wonderful interim solution with many happy patients, but they compromise vision a bit with regard to clarity and certainly with regard to halos and driving at night. With lenses like the Symfony on the horizon, I hope that we will at last have implants that adequately increase depth of focus with little or no visual compromise.

Editors note: Dr. Weinstock has financial interests with Alcon, B+L, and STAAR Surgical (Monrovia, Calif.). Dr. Koch has financial interests with Alcon and AMO. Dr. Henderson has financial interests with Alcon, AMO, and B+L.

Contact information

Henderson
: bahenderson@eyeboston.com
Koch: dkoch@bcm.edu
Weinstock: rjweinstock@yahoo.com

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