IOL innovations optimize outcomes, expand treatment options

New-generation premium IOL technologies offer increasingly accurate refraction customized to individual patients with minimal visual side effects.

Advances in optics, materials and mechanics are driving the development of multifocal, accommodating, toric and extended depth of focus implants.

“It is a changing scenario in which cataract and refractive lens exchange patients can expect considerably better results, major advantages and fewer problems. It is going to be an exciting time, with a lot of innovation in technologies, a brighter future for the patients and expansion for the market,” Jorge L. Alió, MD, PhD, OSN Europe Edition Board Member, said.

In March 2014, the FDA’s Center for Devices and Radiological Health and the American Academy of Ophthalmology held a joint workshop to begin the process of refining the premium IOL review process and developing novel premium IOL study endpoints.

Workshop groups focused on four subtopics: premium IOL safety assessments, patient-reported outcome measures, objective assessment of accommodation and subjective assessment of accommodation.

“There’s clearly a need for IOLs that provide a broader range of vision with little, if any, adverse visual side effects,” Douglas D. Koch, MD, said. Koch represented the AAO at the workshop.

Elizabeth Yeu, MD, who also represented the AAO at the workshop, emphasized the difficulty of developing accommodating or pseudoaccommodating IOLs.

Image: Teresa Cartwright

“The holy grail is some form of presbyopia correction that’s going to give you range of focus but help to minimize the side effects that we currently see,” Yeu said. “Because it is pseudoaccommodating in nature, there is a component of unpredictability in the amount of near vision that is able to be attained. This has been decades in the making, and it has proven to be much more difficult than we realized, and I don’t know, honestly, what the answer is going to be.”

Multifocal and trifocal IOLs

“It would be nice to preserve complete binocularity, meaning good distance, intermediate and near vision in both eyes,” Koch said. “The strategies that people are employing to accomplish this are the pseudoaccommodative lenses. Those strategies that appear to me to be most promising fall into two categories: those that provide pseudoaccommodation like some of the newer multifocal IOLs and certainly the trifocal IOLs, and models like the Symfony (Abbott Medical Optics) that provide extended depth of focus. My European colleagues are very impressed and are quite extensively moving to the trifocal lenses, some of the new bifocals and the Symfony.”

In the U.S., the leading multifocal IOLs currently available include the AcrySof ReStor (Alcon) and the Tecnis IOL (Abbott Medical Optics) with 4 D of near addition and new iterations of the Tecnis with 2.75 D and 3.25 D of near addition.

In Europe, there are various novel diffractive implants and lenses with a new type of refractive varifocal optics.

The Lentis Mplus, the main lens in the varifocal group, is part of a family of lenses developed by Oculentis that focuses on patient selection. The Mplus IOLs are asymmetric, with a sector-shaped near vision zone, the same plate haptics but different additions.

The first Lentis Mplus had a 3 D addition, and the Mplus X was created for better near vision.

Another option offered by Oculentis is the Lentis Comfort, with an addition of 1.5 D. The lower addition sacrifices some near vision but minimizes glare and halos.

The Lentis Mplus toric is individually custom made in a large range for sphere from 0 D to 36 D and for cylinder from 0.25 D to 12 D. It is available in 0.01 D steps to enable the correction of sphere, astigmatism and presbyopia.

“There is also a model for low vision in the Mplus family, which is going to make quite a difference in the lives of patients with AMD who still have sufficient near vision. They are going to be able to read in better conditions and do away with the problems related to spectacles and magnifiers,” Alió said.

Another model, the myLENTIS, is currently under investigation in a European multicenter trial. The lens will be custom made for individual patients.

Damien Gatinel, MD, PhD, was involved in the development of the first trifocal IOL, the FineVision (PhysIOL), released on the European market in 2010.

“What made me think of this lens was that my patients 10 years ago could see well at distance and were able to read, but had trouble using screens. Computer vision was already what they needed most. Computers, smartphones and iPads have now become an integral part of daily life, and the most commonly used reading distance required by our patients is 60 cm to 70 cm. To become spectacle independent, you currently need intermediate vision,” Gatinel said. “There are no disadvantages in trifocal optics, no more halos and glare than in bifocal IOLs, and no more difficulty in IOL power calculation. Whenever you can put a bi, you can put a tri.”

The first FineVision was originally designed with four haptics. When the company decided to introduce a toric model, the design was modified for increased stability. The new double C-loop Pod F is now available as a toric as well as a regular trifocal IOL.

Koch noted the range of vision and satisfaction provided by the FineVision IOL.

“That’s a pretty significant movement that’s taking place there for those folks. Now they find that those patients had a good, continuous range of vision from distance to near, that the halos are no more than they encounter with a multifocal IOL. The patients are pleased by the range of vision that they get,” Koch said.

Other trifocal IOLs include the Alcon AcrySof IQ PanOptix, the Zeiss At Lisa tri and the VSY Acriva Reviol. The latter has a special design aimed at providing superior modulation transfer function values in the transition areas for seamless continuous vision and larger depth of focus.

Polyfocality, multifocal monovision

The WIOL-CF (Medicem), another multifocal system, was renamed “polyfocal.”

“The real difference is the design,” Ioannis G. Pallikaris, MD, PhD, OSN Europe Edition Board Member, said. “A polyfocal optic has no rings, is uniform, but from center to periphery, the optic power continuously changes. It generates a kind of multifocality with a very big depth of focus. Glare problems are overcome, and the effect is huge, 5 D to 7 D. Of course, some compromise with quality of vision has to be expected.”

The manufacturer aimed at creating a bioanalogic implant, close to the size, shape and texture of the human lens. It has no haptics and fills the capsule 90% because it increases in volume by hydration. The posterior curvature is close to the human lens curvature, leading to less formation of posterior capsule opacification, Pallikaris said.

Another area of interest is the multifocal monovision approach, which Pallikaris obtains by combining an intracorneal inlay with a monofocal aspheric IOL.

“I have been using the Presbia Flexivue inlay for years, and now some of the patients have started to develop cataract. I leave the inlay in the cornea, and after IOL implantation, this eye has a kind of multifocal effect. These patients are used to living with multifocality. For them it is not something new because their brain has adapted. Now I have started using this system also in virgin eyes,” Pallikaris said.

“I agree that corneal implants are an intriguing option, either retaining them or adding them at the time of surgery,” Koch added.

Accommodating IOLs

Even though previous accommodating IOL models had limited success, the new generation of lenses may be the future of presbyopia correction, according to Alió.

“Multifocals are not the end of the story. What we need is real accommodation. Once accommodative IOLs are developed adequately, multifocal IOLs will be unable to compete,” he said.

Multifocal optics, Alió said, will always require some degree of adaptation, and there will always be some dissatisfied patients “because our brain is not a multifocal brain, but a monofocal brain.”

Pallikaris expressed a similar view.

“The multifocal concept has undergone major advances and fulfills 70% of the needs of our patients. However, it is still a compromise solution. My belief is that accommodation with a lens that can adjust the power at any given distance is the ultimate goal,” Pallikaris said. “I am very deep into this concept, trying to understand and design a truly accommodative lens, which will be guided by the capsule and not the ciliary body. Real accommodation has to restart in a capsule that is revitalized.”

New accommodating IOLs include the Synchrony dual-optic IOL (Abbott Medical Optics), the FluidVision (PowerVision), the Sapphire (Elenza), the DynaCurve (NuLens) and the Lumina (Akkolens/Oculentis). The Crystalens (Bausch + Lomb) is the only accommodating IOL approved in the U.S.

The FluidVision lens is implanted in the bag. Changes in the bag shape drive fluid into the center and alter the optics of the lens surface.

“PowerVision is probably well known to be the company that is probably furthest along with regard to a new accommodative IOL. That technology relies on a surface curvature change as opposed to a full translation of an optic. That’s always a much more efficient process invoking an optical accommodative change. It seems to be a likely mechanism to achieve good accommodation,” Adrian Glasser, PhD, OSN Optics Board Member and AAO panelist at the workshop, said.

The Lumina is implanted in the sulcus. Power changes are produced by two elements shifting in the plane perpendicular to the optical axis. In a pilot study, the lens was implanted in 50 eyes, and results were compared with those of a standard monofocal IOL.

“The lens showed good results, with evidence of accommodation between 1.5 D and 6 D by objective WAM measurements and subjective defocus curve at 6 months,” Alió said.

Alió said that sulcus-implanted lenses are a better concept because the capsular bag naturally develops fibrosis and atrophy once it is emptied, and there are no functions and no anatomical reasons for it to exist.

“The structural source of kinetic energy is the anterior capsule, which generates axial, centripetal and centrifugal forces that we can exploit to re-establish accommodation,” he said.

A sulcus IOL may prove more stable than other lens designs, at least until a better concept is developed, Yeu said.

“It appears that some form of sulcus IOL is going to be the leader, at least for now, because it seems that it would be easier to develop an accommodating lens that is sulcus in nature that is maybe fixated somehow by the bag for stability purposes. But I honestly don’t know which one is going to take over,” she said. “I know something is going to work, but it’s proving to be very difficult. But I do think it will happen, and I’m not sure how long it will be before a more ideal accommodating lens will be marketed.”

Koch said that, for truly accommodative lenses, there are important issues to sort out in terms of outcomes and complications.

“Three major concerns with IOLs of variable power are, ‘first of all, can you get refractive accuracy at the time of surgery,’ second, ‘will it work long term,’ and third, ‘will they be safe long term.’ In the case of sulcus designs like the Akkolens, we have potential issues with inflammation due to sulcus fixation. In the case of the capsular-supported lenses, such as the FluidVision lens, is that lens going to eventually lose accommodative range if the capsular bag stiffens and does not transmit the movements from the ciliary body? My own bias tends to be against lenses in the sulcus. I’ve seen so many different lenses not do well in the sulcus long term,” he said. “That said, I’ve been wrong plenty of times in the past.”

Koch also said some surgeons prefer the Crystalens, but it has many detractors.

“I think very few of us feel that lens actually accommodates. Many more surgeons have tried it and abandoned it than have continued with it, although there are some superb surgeons who continue to use it. That’s important to acknowledge,” he said.

Design concepts such as a single optic that translates forward and dual optics are not very efficient in providing accommodation, Glasser said.

“Those are certainly still in play from the point of view that people are investigating them, but I don’t think they’re very efficient optical systems in terms of the amount of movement per diopter of accommodation. They’re relatively inefficient. They’re going to have some place in the market, but they’re not going to achieve significant accommodation,” he said.

Extended depth of focus

During the FDA-AAO workshop, the FDA introduced extended depth of focus (EDOF) as a new category of IOLs intended to improve near and intermediate performance without many of the photic phenomena associated with multifocal lenses.

An FDA-AAO task force is developing guidance documents for EDOF IOLs.

One EDOF IOL, the Tecnis Symfony, received the CE mark in Europe but has not yet been approved by the FDA.

“EDOF lenses are going to rock the market, especially if they really are able to do what they say they are able to do reliably, which is provide maybe an extra diopter to 1.5 D of pseudoaccommodation,” Yeu said. “I think that this is going to be a huge player in the market, at least until we find a very, very solid accommodating IOL solution.”

EDOF is an optical concept, not a biomechanical one, Glasser said.

“It’s purely an optical principle where the surface properties of the lens are modified to provide extended depth of focus through something resembling multiple optical zones or multifocality. But they distinguish themselves from multifocals. Obviously, they’re not called multifocals because they have different optical properties that allow them to achieve extended depth of focus,” he said.

The category of EDOF IOLs is not clearly defined, Glasser said.

“It’s expected to have some position in the marketplace. It doesn’t achieve what an accommodative IOL potentially could achieve. But in the interim, until good accommodative IOLs are available, there is a lot of interest in these extended depth of focus IOLs,” Glasser said. “There’s some thought that smarter, cleverer optical designs that can achieve an extended depth of focus can at the same time minimize many [side effects.] Obviously, it depends on how successful the specific designs are and how well they are received by physicians and patients.”

The achromatic technology in the Symfony compensates for chromatic aberration and color distortion, enhancing contrast sensitivity.

“The Symfony operates by using the diffractive rings to essentially eliminate chromatic aberration, which improves the quality of vision such that you get an extended depth of focus,” Koch said. “Plus, I think there’s a very modest diffractive multifocal effect as well. I understand from my European colleagues that patients get some rings but certainly nothing like they would see with a standard diffractive multifocal lens.”

Early results showed that out of 200 eyes, 75 achieved 20/20 or better with the Symfony. Mean intermediate vision was also 20/20, and near vision was in the range of 20/32.

Toric IOLs

Current toric IOLs on the market include the Trulign toric IOL (Bausch + Lomb).

According to Yeu, expanding the range of correction is critical to the development of reliable toric IOLs.

“I think torics are such an amazing platform because there really are very few side effects to them,” Yeu said. “I think, ideally, expanding the range of toricity correction [is] something that would be worthwhile because no matter what, LRIs are really dependent on the hysteresis of the human cornea and the optical zones.”

Yeu said that with the Light Adjustable Lens (Calhoun Vision) a surgeon can correct a specific amount of residual astigmatism.

“I don’t know what newer technologies are coming up beyond adding a toric platform to a multifocal or presbyopia correction lens. That, plus expanding the range of toricity correction, are very exciting and welcome technologies,” Yeu said.

In August, Abbott received FDA approval for and launched three new cylinder powers for its Tecnis toric IOL. The 4.5 D, 5.25 D and 6 D cylinder powers are indicated for astigmatism of 1 D or greater in one or both eyes. – by Michela Cimberle and Matt Hasson

• References:
• Alió JL, et al. J Refract Surg. 2013;doi:10.3928/1081597X-20131021-05.
• Alió JL, et al. J Refract Surg. 2013;doi:10.3928/1081597X-20130318-04.
• Beiko GHH. J Cataract Refract Surg. 2013;39(1):48-55. doi:10.1016/j.jcrs.2012.08.059.
• Developing novel endpoints for premium intraocular lenses (IOL). FDA website. www.fda.gov/downloads/MedicalDevices/NewsEvents/WorkshopsConferences/UCM397127.pdf. March 28, 2014.
• Cochener B, et al. J Refract Surg. 2014;doi:10.3928/1081597X-20141021-08.
• Gatinel D, et al. J Cataract Refract Surg. 2011;doi:10.1016/j.jcrs.2011.05.047.
• Gatinel D, et al. J Cataract Refract Surg. 2013;doi:10.1016/j.jcrs.2013.01.048.
• Pallikaris IG, et al. J Refract Surg. 2014;doi:10.3928/1081597X-20140520-01.
• Plaza-Puche AB, et al. J Refract Surg. 2015;doi:10.3928/1081597X-20150423-03.

• For more information:
• Jorge L. Alió, MD, PhD, can be reached at Vissum Corporation, Avenida de Denia, s/n, 03016 Alicante, Spain; email: jlalio@vissum.com.
• Damien Gatinel, MD, PhD, can be reached at Fondation Rothschild, 25 Rue Manin, 75019 Paris, France; email: gatinel@gmail.com.
• Adrian Glasser, PhD, can be reached at College of Optometry, University of Houston, 4901 Calhoun Road, 505 J. Davis Armistead Building, Houston, TX 77204; email: aglasser@uh.edu.
• Douglas D. Koch, MD, can be reached at Baylor College of Medicine, Department of Ophthalmology, 6565 Fannin, NC205, Houston, TX 77030; email: dkoch@bcm.tmc.edu.
• Ioannis G. Pallikaris, MD, PhD, can be reached at University Hospital of Heraklion, Ophthalmological Clinic, P.O. Box 1352, Voutes, Heraklion, CR-71003, Crete, Greece; email: pallikar@med.uoc.gr.
• Elizabeth Yeu, MD, can be reached at Virginia Eye Consultants, Norfolk Office, Office & Surgery Center, 241 Corporate Blvd., Norfolk, VA 23502; email: eyeulin@gmail.com.

Disclosures: Alió reports he is a consultant to Akkolens, Oculentis and Zeiss. Gatinel reports he holds proprietary interest in the trifocal diffractive technology (patent WO2011092169). Glasser reports he is a consultant for PowerVision. Koch reports he is a consultant for Alcon, Abbott Medical Optics and ReVision Optics and serves on the board of PowerVision. Pallikaris reports he is on the medical advisory board of Presbia. Yeu reports she is a consultant for Abbott Medical Optics and Alcon.

Which approach to presbyopia correction is more viable, multifocal IOLs or monovision with monofocal IOLs?

Monovision is preferred for better intermediate vision

Monovision is not only viable, but the most common treatment currently used by U.S. surgeons to improve intermediate and near vision. Named “blended” or mini-monovision, surgeons target for plano to –0.25 D in the dominant eye and –1.25 D to –1.5 D in the nondominant eye. It has little or no effect on depth perception or stereopsis, provides excellent intermediate vision (66 cm to 80 cm or 26 in to 31 in), and in good light, most patients can read 20/20 print without difficulty at the normal reading distance (40 cm or 16 in). Patients rarely report halos or glare and have no problems driving at night without glasses. If the print is too small or the illumination inadequate, +1 D readers are all that is needed. Surgeons are not faced with the occasional unhappy patient with a multifocal IOL for whom lens exchange is the only treatment.

If the patient desires no glasses for reading small print in dim illumination and understands there is a slight sacrifice in retinal image contrast and the increased probability of halos and glare at night, then multifocal IOLs provide an excellent alternative. True accommodating IOLs are on the horizon and should provide the same high-quality distance vision as with monofocals and excellent near vision as with multifocals without any compromise.

Jack T. Holladay, MD, MSEE, FACS, is OSN Optics Section Editor. Disclosure: Holladay reports no relevant financial disclosures.

Multifocals offer full spectacle independence

Both multifocal IOL and pseudophakic monovision approaches, whether with monofocal or accommodating IOLs, are highly effective at correcting presbyopia. Multifocal IOLs have the advantage of giving clear binocular vision for distance and near, good depth perception and a consistently high rate of spectacle independence.

Monovision with monofocal or accommodating IOLs also yields a high rate of spectacle independence with a distinct advantage: The patient can obtain superior nighttime driving vision when wearing spectacle or contact lens correction for the near eye.

Which approach is better? For the motivated patient aiming for full spectacle independence, multifocal IOLs are my go-to approach. Most patients who present for refractive lens exchange in a refractive surgery practice fit this description. Multifocal IOLs consistently deliver the highest rate of spectacle independence among surgical options in my hands, an observation that has been validated in the literature. Our approach is to implant the Tecnis ZKB00 (Abbott Medical Optics) in both eyes using intraoperative aberrometry in an in-office vision correction suite.

With careful patient selection, counseling, preoperative testing and surgical technique, a majority of patients can be highly satisfied with either of these approaches to presbyopia correction.

Jason P. Brinton, MD, is an OSN Refractive Surgery Board Member. Disclosure: Brinton reports financial relationships with Alcon, Abbott Medical Optics, Nidek and STAAR Surgical.