Burgeoning phaco technologies improve visual outcomes and safety

Trio of innovative approaches minimizes complications, provides precise IOL fixation, surgeons say.

Small-incision techniques and novel modes of ultrasound energy are poised to minimize risks and optimize outcomes for phacoemulsification patients who have increased expectations.

In addition, new handpieces and femtosecond lasers may raise safety and efficacy to new levels.

“The trends in phaco technology are really in two different directions,” according to David F. Chang, MD, OSN Cataract Surgery Board Member. “One trend is in trying to make incisions smaller, via the so-called microincisional cataract instrumentation. The other direction, in terms of phaco equipment and platforms, has certainly been in the reduction of longitudinal ultrasound to improve lens followability.”

David F. Chang

Rosa Braga-Mele, MD, FRCSC, OSN Cataract Surgery Section Editor, said that femtosecond laser technology has the potential to bring safe and precise cataract surgery within reach for surgeons of varying skill levels.

“We’re going to see better sealability with these wounds, more precision with the wounds, and more precise and stronger capsulorrhexis with femtosecond laser technology being able to perform that,” Dr. Braga-Mele said. “That’s going to make it more of a level playing field for everybody to do surgery. I don’t think your skill level is necessarily going to have to be quite as high.”

As baby boomers age, femtosecond lasers will likely help fuel a surge in refractive lens exchange with premium lenses, Randall J. Olson, MD, OSN Cataract Surgery Board Member, said.

“There’s real value to it for the patient, and there’s actually real value for the insurance companies and Medicare, because a lenticular procedure done is a procedure that they don’t have to pay for down the road,” Dr. Olson said. “It’s basically a triple win.”

Maximized outcomes from small incisions

The microcoaxial approach, which allows incisions of 2.2 mm to 2.4 mm, is more adaptable than the biaxial method but presents its own challenges, Dr. Chang said.

“There’s no question that microcoaxial is more popular and an easier transition to make compared to biaxial microincisional cataract surgery,” he said. “The challenge then becomes getting the lens implant through the smaller incision.”

However, in many cases, incision size is not as important as the choice of lens to ensure the best possible refractive outcome.

“Certainly we will utilize whatever incision size is needed to put in the lens implant that the patient chooses,” Dr. Chang said. “For example, even if it requires a 3.8-mm incision, the patient will enjoy the benefits of an accommodating IOL for the rest of their life, and this is far more important than the theoretical short-lived advantages of a smaller incision.”

At the upcoming American Society of Cataract and Refractive Surgery meeting in Boston, Dr. Braga-Mele and colleagues plan to present data showing that enlarging a 1.8-mm phaco wound to 2.7 mm for IOL insertion led to less surgically induced astigmatism than performing the entire procedure through a 2.7-mm wound.

Rosa Braga-Mele

“You still have an advantage, even if you add the step at the end to put the IOL in,” Dr. Braga-Mele said. “That’s because you’re creating less torque on the entire wound. That extra millimeter that you open up is really just to slip the lens in and out. It doesn’t cause any astigmatism and it heals very rapidly.”

The smaller incision required less balanced salt solution and caused less turbulence, resulting in less damage to the corneal endothelium, Dr. Braga-Mele said.

Yet, despite recent gains, small incisions may have reached a plateau in terms of maximizing outcomes, she said.

“I don’t know if we need to go any smaller in incision size,” Dr. Braga-Mele said. “For now, I think we’ve maximized our outcomes with small-incision surgery.”

Handpieces, ultrasound

The OZil torsional handpiece (Alcon) emerged as a leading phaco device in a Web-based survey of more than 1,000 surgeons that Dr. Olson and colleagues recently conducted. The OZil handpiece is used with Alcon’s Infiniti Vision System.

“The market has spoken loud and clear, and we really like horizontal ultrasound,” he said. “[Surgeons] particularly like the loss of chatter.”

The OZil handpiece and the Ellips handpiece with transversal ultrasound (Abbott Medical Optics) offer non-longitudinal movement of the phaco tip, minimizing chatter.

“This clinically will appear as better followability of fragments that are presenting to the tip,” Dr. Chang said. “Better followability is the same thing as reduced chatter and turbulence of particles at the tip that would be bombarding the corneal endothelium. Particularly with denser nuclei, this gives a noticeable reduction in postop day 1 corneal edema.”

The Ellips handpiece works well with a straight phaco tip, while the OZil requires some bending of the phaco tip to create sufficient cutting movement, he said.

“But both work extremely well and they’re both very popular,” Dr. Chang said. “I think that virtually all surgeons who have these modalities available to them on their current phaco platform are employing them routinely.”

Phacoemulsification with the Infiniti Intrepid and OZil handpiece through a 2.2-mm incision enhances chamber stability and safety, Dr. Braga-Mele said. However, she said that in the future she would ideally like to see a smaller, more ergonomic handpiece with manual controls.

“What I’d really like to see is a handpiece that allows you to control phaco on the handpiece,” she said. “That would be fantastic. You wouldn’t need a foot pedal if you could have something like a stick shift in your finger to move from position to position.”

Femtosecond lasers offer precision

The IntraLase femtosecond laser (Abbott Medical Optics) is used in some cataract procedures. Three companies — LenSx Lasers, LensAR and OptiMedica — are developing femtosecond laser platforms specifically for cataract surgery. The LenSx platform is approved in the U.S. for capsulotomy.

Dr. Olson envisioned the creation of a perfect incision and capsulorrhexis with femtosecond laser.

“I have absolutely no doubt in my mind that with femtosecond laser, we can guarantee a perfect incision,” he said. “The newer premium intraocular lenses that are particularly exciting are going to demand a perfectly sized, centered capsulorrhexis.”

Dr. Chang noted the potential benefits and challenges of femtosecond cataract surgery.

“The technology really has the potential to automate many of the more difficult steps of the cataract procedure, starting with the cataract incision, the astigmatic cuts in the cornea and the capsulorrhexis,” he said. “Most intriguing, it has the ability to soften or even section the nucleus, analogous to possibly pre-chopping the nucleus for phacoemulsification. One challenge will be how to efficiently integrate this with the conventional phaco technology that we still need to remove the lens tissue, as well as how to pay for this technology.”

Existing femtosecond laser technology is particularly suited to making a precise capsulorrhexis. In the future, femtosecond lasers may enable the precise fixation of presbyopia-correcting IOLs and, potentially, liquid lenses, Dr. Braga-Mele said.

“That’s what I’d like to see happen, where we have everything very controlled,” she said. – by Matt Hasson

• Rosa Braga-Mele, MD, FRCSC, can be reached at 245 Danforth Ave., Suite 200, Toronto, Ontario M4K 1N2, Canada; 416-462-0393; e-mail: rbragamele@rogers.com. Dr. Braga-Mele is a consultant for AMO, Alcon and Bausch & Lomb.
• David F. Chang, MD, clinical professor at the University of California, San Francisco, can be reached at 762 Altos Oaks Dr., Suite 1, Los Altos, CA 94024; 650-948-9123; e-mail: dceye@earthlink.net. Dr. Chang is a consultant for Abbott Medical Optics, Alcon, and LensAR.
• Randall J. Olson, MD, can be reached at John A. Moran Eye Center, 65 Medical Dr., North Tower, Salt Lake City, UT 84132; 801-585-6622; e-mail: randallj.olson@hsc.utah.edu. Dr. Olson is a consultant for AMO.

I can envision a not-too-distant future in which the bulk of what we as phaco surgeons have learned to do becomes obsolete thanks to femtosecond technology. Even today, with the unsurpassed ease of lens extraction utilizing the Signature Ellips or Infiniti OZil, a relatively greater proportion of my time in the operating room is devoted to refractive considerations using the WaveTec ORange intraoperative aberrometer to refine astigmatism correction and verify IOL power calculations. With the introduction of the Synchrony dual optic accommodative IOL in the next year, a premium will be placed on perfect incisions and capsulorrhexis construction, which will benefit from femtosecond technology, as well as meticulous cortical and lens epithelial cell cleanup, which will require patience and skill. The demands on surgeons are changing, from a focus on getting the cataract out to a focus on what you are putting in.

– Mark Packer, MD
Drs. Fine, Hoffman and Packer, Eugene, Ore.