Technology, demand drive laser- and lens-based presbyopia correction

The number of aging patients with presbyopia is expected to mushroom in the coming years. But as they face the inevitable visual effects of aging, these patients have a growing array of treatment options at their disposal.

New developments in technology spur innovations that enable cataract and refractive surgeons to meet rising patient expectations. The symbiotic relationship between growing demand for strong outcomes and available treatments promises to persist for years to come.

An upsurge in presbyopic lens procedures is likely to continue as baby boomers begin to turn 65 years old this year, Jay S. Pepose, MD, PhD, said.

“Just the absolute number of people in this age cohort is staggering,” he said. “We’ve seen sustained growth in the overall cataract patient population and in the patients choosing presbyopic lenses.”

The economic downturn has had an adverse effect on laser vision correction, Dr. Pepose said.

“The laser vision patients are generally younger than refractive lens patients,” he said. “They have less financial means, less discretionary income and probably a lot less savings than the older patients who already put their kids through college and already paid off most or all of their mortgages.”

Daniel S. Durrie, MD, OSN U.S. Edition Refractive Surgery Section Editor, echoed Dr. Pepose’s observations.

Elizabeth A. Davis, MD, FACS, envisions presbyopia correction becoming a standard component of cataract surgery. Image: Shari Fleming Photography

“There doesn’t seem to have been any less interest from patients in getting rid of reading glasses and bifocals,” Dr. Durrie said. “There’s strong interest from the patients.”

Elizabeth A. Davis, MD, FACS, OSN U.S. Edition Cataract Surgery Board Member, attributed surging demand to a growing acceptance of presbyopia correction coupled with high expectations.

“Even as of 2 years ago, patients really did not have as great expectations of freedom from glasses for all distances with cataract surgery,” Dr. Davis said. “But now there is that expectation of not only reduced dependence on glasses or contacts for distance vision but for near vision as well.”

Growth in Europe and Asia

H. Burkhard Dick, MD, OSN Europe Edition Chairman of the Editorial Board, works in a university setting that is a center of excellence for the treatment of presbyopia in Germany.

“Patients come to us from far specifically for our expertise in this field. As the various techniques become increasingly reliable, the number of patients increases. There is a lot happening around presbyopia. Industries are making huge investments, and the market is very hot,” he said.

H. Burkhard Dick

Jorge L. Alió, MD, OSN Europe Edition Board Member, said that presbyopia correction represents 25% of the total volume of surgical procedures at the Vissum Institute in Alicante, Spain.

“We have now the return wave of so many patients who were implanted with monofocal IOLs and want presbyopic treatments. They are mainly professionals like doctors and lawyers and business people,” Dr. Alió said.

In developing countries in Asia, the presbyopia surgery market is growing at an even faster rate. An emerging middle class views refractive surgery as a status symbol and a lifestyle choice, Cyres K. Mehta, MD, OSN Asia-Pacific Edition Board Member, said.

“Young urban professionals who hit 40 do not want to be encumbered with near glasses. They are mainly information technology professionals, students and young entrepreneurs who spend many hours a day in front of a computer screen,” Dr. Mehta said.

“Europe is a developed market where the penetration of presbyopic LASIK is still percentage-wise higher, but I feel that in coming years the action will be in China and India, due to the huge population and their growing buying power,” he said.

Presbyopic LASIK

Monovision is the only viable LASIK option for correcting presbyopia, Dr. Davis said.

“There are some multifocal ablations in development, but those aren’t mainstream and there is risk of loss of best corrected visual acuity and loss of contrast sensitivity that may be unacceptable in a good number of cases,” she said.

Dr. Durrie also said monovision is the mainstay of presbyopic LASIK, despite a growing interest in presbyLASIK.

In 2001, Alain Telandro, MD, a pioneer in LASIK presbyopia correction in Cannes, developed a method of multi-zone presbyopic LASIK and helped design Nidek PAC software for the Nidek 5000 laser. The idea was that creating a progressive aspheric lens on the corneal surface would provide a flatter optical zone in the center for distance vision and a progressive change of curvature toward the periphery for intermediate and near vision.

In recent years, several excimer laser platforms have incorporated presbyopic LASIK applications. With Schwind, Dr. Alió developed the PresbyMax software using the Amaris platform. His presbyLASIK approach has a central zone for near vision and periphery for distance vision.

“This technique is still in development. Over the last 4 years, we have progressively upgraded the software. We are now at the third version, and results are increasingly better. We use PresbyMax with any type of refraction, from –7 D to +4 D, with astigmatism up to 2 D,” Dr. Alió said.

The aim is to compensate 2 D of presbyopia, equivalent to 3 D of an IOL. The treatment is performed bilaterally, which makes 2 D sufficient to address intermediate and advanced presbyopia.

PresbyMax is also used in Asia, particularly in India. For Dr. Mehta, it is the procedure of choice for patients in the 40- to 49-year age range with no evidence of cataract. He said that patients must be warned that distance vision will be suboptimal for the first few months after surgery and that the near add might decrease slightly over time.

“Also, I don’t perform it in patients who drive long distances at night. It is definitely not the best option for night drivers in India, due to the congested roads with oncoming headlights,” Dr. Mehta said.

Other laser platforms for presbyopia treatment include the Custom Q module of the Allegretto Wave (Alcon), the laser blended vision procedure of the Mel 80 (Carl Zeiss Meditec) and the CustomVue technology of Visx (Abbott Medical Optics).

Despite positive reviews from some quarters, presbyLASIK is not ready for prime time, Dr. Durrie said.

“There are some people who think it doesn’t work at all and some people who think it’s great. I think it needs some scientific rigor to do some clinical trials,” he said.

Dr. Durrie said a randomized prospective study comparing monovision with presbyLASIK would be helpful.

Lenses

Dr. Pepose said there is utility in the Crystalens accommodating IOL (Bausch + Lomb) with aspheric optics (AO). The Crystalens, which is also available in HD and Five-0 versions, is the only accommodating IOL approved by the U.S. Food and Drug Administration.

“It’s more forgiving with regard to its defocus curve. … If you don’t hit exactly emmetropia, if you’re off a quarter or half a diopter, it doesn’t impact the vision as much,” Dr. Pepose said. “The zero-aberration aspheric optics improve the image quality more than the HD, which is a spherical lens.”

Jay S. Pepose

Dr. Pepose said he uses the Crystalens Five-0, which is available in lower powers than the AO, in high myopes and in hyperopic LASIK patients with high residual negative spherical aberration.

“I’m going to implant the lens that’s got a little bit of plus spherical aberration to offset some of the negative spherical aberration that results from hyperopic LASIK, if it was a really high treatment. Otherwise, I’ll go with the Crystalens AO, even in my post-LASIK patients,” Dr. Pepose said.

The accommodating dual-optic Synchrony IOL (AMO) has undergone phase 3 clinical trials, Dr. Pepose said.

Dr. Davis said she has a strong preference for the Tecnis multifocal IOL (AMO).

“I’ve used all of them, and I feel it gives the highest patient satisfaction, the greatest predictability and the best quality of vision,” Dr. Davis said.

In patients older than 60 years, Dr. Alió performs refractive lens exchange (RLE) or cataract surgery with implantation of a multifocal lens. The lenses he uses are, in order of preference, the Lentis Mplus (Oculentis), the Acri.Lisa and the toric Acri.Lisa (both Carl Zeiss Meditec). He also uses the Crystalens and Synchrony in a minority of cases.

“I prefer multifocal rather than accommodative lenses because they provide a wider range of correction,” he said. “As the technology evolves, accommodative IOLs might eventually be the winners because they are a more physiological concept, but for now the outcomes of multifocal IOLs are better.”

Dr. Dick said he prefers accommodating lenses for his patients.

“The multifocal concept is definitely a compromise, and it’s not my favorite solution. Photic phenomena cannot be avoided. They are inherent to the system, and some patients accept them, some do not,” he said.

Of the 4,000 cataract patients who are annually treated in Dr. Dick’s clinic, 5% to 8% are implanted with accommodating or multifocal IOLs.

He offers multifocal lenses — the Tecnis one-piece and three-piece, the ReZoom (AMO), the M-flex (Rayner), the ReSTOR (Alcon) and the Lentis Mplus — to patients who want to be 100% spectacle independent.

“With accommodative lenses, patients should know they might need a little add for near tasks like reading books. However, they are perfect for those who want to be spectacle independent for computer work rather than reading,” he said.

Dr. Dick said the Synchrony has a low posterior capsule opacification rate and relatively high accommodative amplitude. The Crystalens requires a 2.2-mm clear corneal incision but offers slightly less accommodation than required.

“Both lenses have weaknesses and strength. With the Synchrony, PCO rate is very low and you can achieve an accommodative amplitude of 1.75 D,” he said. “I have implanted about 130 of these lenses, and patients are extremely satisfied. Certainly it is quite a bulky IOL that needs a fairly large 3.6- to 3.8-mm incision, mandatorily posterior or sclerocorneal, if you want to avoid astigmatism. The Crystalens needs a smaller 2.2-mm incision in clear cornea, but accommodation is slightly less and some patients need a near add.”

Monovision LASIK is his alternative for patients with a clear lens and low ametropia. With more than +3 D, RLE is better because high hyperopes are good candidates for RLE and bad candidates for LASIK, Dr. Dick said.

Because of the amount of sunlight exposure in India, early cataract occurring around the age of 50 years is common, Dr. Mehta said.

“I offer multifocal lenses to all these patients. I also perform RLE in patients with a clear lens who are not good candidates for corneal laser surgery, like night drivers. My favorite lenses for this subgroup of patients are the diffractive ReSTOR +3 D and the new generation of refractive multifocals from Rayner,” he said.

Intrastromal correction and inlays

The IntraCor procedure provides flapless intrastromal correction using the Femtec femtosecond laser (Technolas Perfect Vision) to reshape the cornea without affecting the surface. The refractive power of the cornea is locally changed, leading to significantly improved near vision and good intermediate vision with a little sacrifice of distance vision.

Emmetropic patients who desire independence from reading spectacles at the onset of presbyopia are eligible for corneal inlays.

The Kamra inlay (AcuFocus) is an opaque micro-disc with a circular aperture in the center, exploiting the pinhole effect to increase depth of field.

The inlay has shown some promise, particularly in combination with LASIK, Dr. Pepose said.

Patients are targeted to a small amount of monovision.

“With the inlay blocking unfocused light, they’re getting very good distance and very good near,” Dr. Pepose said. “I think that it represents a most promising technology. It would also be interesting to see if that same type of small-aperture design could be applied in other ways, not just at the cornea, but also if it could be coupled with the lens implant.”

Dr. Dick uses the Kamra inlay in a select minority of emmetropic presbyopes.

“I use the femtolaser and a special mask to implant the device into the cornea at a depth of about 220 µm. For cosmetic reasons, I use it only in patients with brown eyes, and results are very good,” he said.

Other inlays currently being investigated are the InVue (BioVision) and the PresbyLens (ReVision Optics).

Into the future

Dr. Davis said she envisions presbyopia correction becoming a standard component of cataract surgery.

“I think there will come a time where it’s pretty much the norm and standard of care, that when a patient undergoes a surgery, and if we have the capability, that we correct their vision fully,” Dr. Davis said. “The technology in this area is just improving exponentially.”

Dr. Durrie voiced a similar view.

“My feeling is that since it’s going to continue to grow significantly in the next 10 to 20 years, it’s going to be something that patients will be having done all the time,” he said.

Presbyopia is, to date, the refractive condition with the widest range of treatment options. However, none of these options is entirely satisfying, and all entail varying degrees of visual compromise.

“Multifocal implants cause photic phenomena and lead to a loss of contrast sensitivity. Presbyopic LASIK strategies can lead to decreased distance vision, and monovision leads to decrease in stereopsis. The ideal strategy, I feel, will be refillable lenses or accommodating IOLs and probably not a corneal solution,” Dr. Mehta said.

“There are techniques that seem promising in early trials, such as the customized near add procedure with the Light Adjustable Lens (Calhoun Vision), where a small add zone is written in the central part of the lens and can be changed to adjust to the patient’s requirements before being locked in,” Dr. Dick said. “The add-on lens technology is also interesting, and there is a huge number of new lenses for presbyopia coming up. It’s very impressive.”

An emerging accommodating lens, the NuLens, comprises a piston activated by the ciliary muscles that pushes a flexible silicone gel through a small hole, forming a bulge that acts as a lens.

The NuLens yielded positive visual outcomes and was well-tolerated, according to a pilot study that Dr. Alió and colleagues published in the Journal of Refractive Surgery.

Currently, the NuLens manufacturer is refining how the IOL is linked to the accommodation and disaccommodation mechanism, Dr. Pepose said.

Emerging presbyopia correction techniques also include LaserACE, which is designed to restore the natural mechanism of accommodation. A diamond pattern of nine diamond-shaped full-thickness scleral ablations is made using the VisioLite Er:YAG laser in four oblique-oriented quadrants of the anterior part of the scleral wall to release the pressure and restore the flexibility of the sclera. – by Michela Cimberle and Matt Hasson

Which is the future of presbyopia correction, multifocality or accommodation, and why?

References:

• Alió JL, Amparo F, Ortiz D, Moreno L. Corneal multifocality with excimer laser for presbyopia correction. Curr Opin Ophthalmol. 2009;20(4):264-271.
• Alió JL, Chaubard JJ, Caliz A, Sala E, Patel S. Correction of presbyopia by technovision central multifocal LASIK (presbyLASIK). J Refract Surg. 2006;22(5):453-460.
• Alió JL, Elkady B, Ortiz D, Bernabeu G. Clinical outcomes and intraocular optical quality of a diffractive multifocal intraocular lens with asymmetrical light distribution. J Cataract Refract Surg. 2008;34(6):942-948.
• Dick HB. Accommodative intraocular lenses: current status. Curr Opin Ophthalmol. 2005;16(1):8-26.
• Dick HB, Dell S. Single optic accommodative intraocular lenses. Ophthalmol Clin North Am. 2006;19(1):107-124.
• Epstein RL, Gurgos MA. Presbyopia treatment by monocular peripheral presbyLASIK. J Refract Surg. 2009;25(6):516-523.
• Holzer MP, Mannsfeld A, Ehmer A, Auffarth GU. Early outcomes of INTRACOR femtosecond laser treatment for presbyopia. J Refract Surg. 2009;25(10):855-861.
• Ortiz D, Alió JL, Bernabéu G, Pongo V. Optical performance of monofocal and multifocal intraocular lenses in the human eye. J Cataract Refract Surg. 2008;34(5):755-762.
• Patel S, Alió JL, Feinbaum C. Comparison of Acri. Smart multifocal IOL, crystalens AT-45 accommodative IOL, and Technovision presbyLASIK for correcting presbyopia. J Refract Surg. 2008;24(3):294-299.
• Pinelli R, Ortiz D, Simonetto A, Bacchi C, Sala E, Alió JL. Correction of presbyopia in hyperopia with a center-distance, paracentral-near technique using the Technolas 217z platform. J Refract Surg. 2008;24(5):494-500.
• Ruiz LA, Cepeda LM, Fuentes VC. Intrastromal correction of presbyopia using a femtosecond laser system. J Refract Surg. 2009;25(10):847-854.
• Telandro A. Pseudo-accommodative cornea: a new concept for correction of presbyopia. J Refract Surg. 2004;20(5 Suppl):S714-S717.

• Jorge L. Alió, MD, PhD, can be reached at Vissum Corporation, Avenida de Denia, s/n, 03016 Alicante, Spain; 34-965150025; fax: 34-965151501; e-mail: jlalio@vissum.com.
• Elizabeth A. Davis, MD, FACS, can be reached at Minnesota Eye Consultants, 9801 Dupont Ave. South, Bloomington MN 55431; 952-567-6067; fax: 952-885-9942; e-mail: eadavis@mneye.com.
• H. Burkhard Dick, MD, can be reached at Center for Vision Science, Ruhr University Eye Hospital, In der Schornau 23 – 25, DE-44892 Bochum, Germany; 49-234-2993101; fax: 49-234-2993109; e-mail: burkhard.dick@kk-bochum.de.
• Daniel S. Durrie, MD, can be reached at Durrie Vision, 5520 College Blvd., Suite 200, Overland Park, KS 66211; 913-491-3330; fax: 913-491-9650; e-mail: ddurrie@durrievision.com.
• Cyres K. Mehta, MD, can be reached at International Eye Centre, Mistry Chambers, Ground Floor, Brahmakumaris Marg, Mumbai 400005, India; 91-22-652-61579; e-mail: cyresmehta@yahoo.com.
• Jay S. Pepose, MD, PhD, can be reached at Pepose Vision Institute, 16216 Baxter Road, Suite 205, Chesterfield, MO 63017; 636-728-0111; fax: 636-728-0287; e-mail: jpepose@peposevision.com.
• Disclosures: Dr. Alió is a consultant for Schwind Amaris, with a consultancy agreement and royalties from PresbyMax. He is a consultant and researcher for Oculentis; a clinical investigator of Carl Zeiss Meditec’s toric and Acri.Lisa lenses; and a clinical investigator for Abbott Medical Optics in the Visiogen project and a clinical investigator for AcuFocus and Presbia. He has no financial interest in the Crystalens but is a consultant for Bausch + Lomb. Dr. Davis is a consultant for Abbott Medical Optics and Bausch + Lomb. She is an owner and has equity in Refractec. Dr. Dick has received research grants and is a consultant for Abbott Medical Optics. He is a clinical investigator for the Crystalens AO and the Kamra inlay. He holds stock options in the Light Adjustable Lens (Calhoun Vision). Dr. Durrie is a clinical investigator for Alcon and Abbott Medical Optics. Dr. Mehta has no direct financial interest in the products discussed in this article, nor is he a paid consultant for any companies mentioned. Dr. Pepose has a financial interest in AcuFocus, Abbott Medical Optics and Bausch + Lomb.