Advanced multifocal IOLs increase range of presbyopia correction

Recent advances such as apodized diffractive optics and toric features yield high patient satisfaction, physician says.

Hiroko Bissen- Miyajima

New multifocal IOL designs incorporate innovative optical concepts to correct presbyopia and enhance quality of life, a surgeon said.

Some lens designs improve intermediate vision as well as near and distance vision, and some incorporate toric features to correct astigmatism, Hiroko Bissen-Miyajima, MD, said at the American Society of Cataract and Refractive Surgery and Japanese Society of Cataract and Refractive Surgery Joint Symposium in San Diego, U.S.A.

“We targeted distance and near, but nowadays we recognize the importance of intermediate vision,” she said. “We have low additional power, and in the future we will have a diffractive design with distance, near plus intermediate.”

Dr. Bissen-Miyajima drew a parallel between the evolution of cellular telephones and multifocal IOLs since 1987, when the analog cellular phone and PMMA IOL were introduced.

“In 2010 or 2011, we now have the option of lower near addition or a multifocal lens with toric function,” Dr. Bissen-Miyajima said.

Recent multifocal IOL developments include the AcrySof IQ ReSTOR multifocal toric IOL, ReSTOR apodized diffractive IOL (both Alcon), Tecnis multifocal IOL (Abbott Medical Optics), Acri.Lisa multifocal toric IOL (Acri.Tec) and Hoya’s new diffractive multifocal IOL with or without toric function.

The Hoya lens is a single-piece, hydrophobic acrylic, aspheric implant with toric or non-toric capability. It has near additional power of +3.5 D and is contained in a preloaded system.

A model eye study of the Hoya lens with an aperture size of 3 mm showed that the new lens improved intermediate vision more than the company’s current diffractive lens did, Dr. Bissen-Miyajima said.

“We expect to have the same result with the clinical cases, and I hope I can show you soon,” she said.

Different additional power

Two diffractive IOLs feature different additional powers: the AcrySof IQ ReSTOR SN6AD3 with +4 D additional power and the AcrySof IQ ReSTOR SN6AD1 with +3 D additional power, Dr. Bissen-Miyajima said.

Study results showed that the ReSTOR with a +4 D addition had the spectacle plane at 3.2 D, which provided good near visual acuity at 30 cm. The ReSTOR with a +3 D addition had the spectacle plane at 2 D, which improved near visual acuity at 40 cm, Dr. Bissen-Miyajima said.

The ReSTOR with +4 D addition improved decimal near vision at 30 cm by 0.65, intermediate vision at 50 cm by 0.67 and distance vision by 1.09.

The ReSTOR with a +3 D add improved near vision at 30 cm by 0.58, intermediate vision at 50 cm by 0.82 and distance vision by 0.92.

A defocus curve showed that the +4 D ReSTOR offered peak vision at 0 D and 3 D. The +3 D ReSTOR provided peak vision at 0 D and 2 D.

“The good thing about +3 D addition is the decrease of intermediate vision is smaller compared to the +4 D,” Dr. Bissen-Miyajima said. “That’s why, I think, this lens is well chosen in Western countries, because the lifestyle might be a little bit different from our [life]style.”

The AcrySof IQ ReSTOR IOLs with different additional power also reduced spectacle dependence. For example, 3.6% of patients who received the +4 D ReSTOR wore glasses for intermediate vision and reading. Among patients who received the +3 D ReSTOR, none wore glasses for intermediate vision and 15.6% wore glasses for reading, Dr. Bissen-Miyajima said.

Add-on IOLs

Add-on or “piggyback” IOLs are a viable and sometimes preferable alternative to IOL exchange surgery, Dr. Bissen-Miyajima said.

She discussed the case of a 58-year-old woman who had undergone LASIK and subsequent cataract surgery in the left eye. The patient developed posterior capsular opacity and underwent Nd:YAG capsulotomy. During an office visit, the patient saw information about multifocal lenses and requested an IOL exchange.

Dr. Bissen-Miyajima and colleagues opted to give the patient an add-on lens.

“All of you can remove the lens from the capsule, but you know how much time you need, and you need to cut the haptics and you need to cut the optics, but putting on this lens is easy,” Dr. Bissen-Miyajima said. “You just put viscoelastics and implant the additional lens in the sulcus, in comparison to taking the risk of breaking the posterior capsule during an IOL exchange.”

Piggyback IOL implantation improved the patient’s near vision, left her distance vision unaffected and resulted in normal contrast sensitivity.

A 73-year-old woman also wanted to undergo IOL exchange, Dr. Bissen-Miyajima said. She chose to implant an add-on IOL with spherical power of –6 D and +3.5 D of additional power.

The procedure offered positive visual and refractive outcomes, and the patient was highly satisfied, Dr. Bissen-Miyajima said.

“I prefer adding a lens than exchanging the lens,” she said. – by Matt Hasson

• Hiroko Bissen-Miyajima, MD, can be reached at Department of Ophthalmology, Tokyo Dental College, Suidobashi Hospital 2-9-18 Misaki-cho, Chiyoda-ku Tokyo 101-0061, Japan; +81-3-3262-3421; fax: +81-3-5275-1912; email: bissen@tdc.ac.jp.
• Disclosure: Dr. Bissen-Miyajima is a consultant for Abbott Medical Optics and Hoya.