Instrumentation, imaging, optics drive advances in cataract surgery

Femtosecond laser methods are gaining momentum, but versatile phacoemulsification technologies still offer high levels of safety, accuracy.

Roger F. Steinert

New developments in handheld instrumentation and laser technology continue to raise the bar for cataract surgery by reducing complications and optimizing visual outcomes.

In addition, improved biometry and intraoperative aberrometry help surgeons visualize anterior segment anatomy and enhance visual and refractive outcomes.

A recent advance that has received much of the attention is femtosecond laser-assisted cataract surgery. Many ophthalmologists are now focused on the potential for femtosecond lasers to enable superior capsulorrhexis design and optimize effective lens position and lens power, Roger F. Steinert, MD, OSN Cornea/External Disease Board Member, said.

“There are plenty of data showing that laser capsulotomies are predictable, reliable and reproducible, as they should be,” Dr. Steinert said. “Time will tell, but I think we’ll start to get answers on improved clinical outcomes. Those of us involved in this technology believe it will translate into better outcomes that are important to the patient. But now we have to prove it.”

Femtosecond cataract surgery will likely engender new techniques that require novel instrumentation, Bonnie An Henderson, MD, OSN Cataract Surgery Board Member, said.

“Even though the bulk of the procedure is still going to be quite similar to traditional phacoemulsification, I do think that you will need some different instruments,” Dr. Henderson said.

For example, because a femtosecond laser makes an incision about 99% of the way through the cornea, a blunt instrument is required to break through the remaining 1%. New instruments will also be required to complete femtosecond laser-created capsulorrhexes, peel away remaining epinuclear shell material and clear bubbles created during femtosecond laser procedures, Dr. Henderson said.

“There are all sorts of scenarios that may come up that we haven’t even thought about,” she said.

Recent strides in phaco

Bonnie An Henderson

Recent improvements to major phacoemulsification platforms include flexible fluidic settings that enable surgeons to safely tackle hard lens nuclei, Dr. Henderson said.

“Several advances that occurred a few years ago are still beneficial today. Changes in the movement of the handpiece — such as the OZil torsional handpiece, which is used with the Infiniti Vision System (Alcon), and the Ellips FX handpiece, used with the WhiteStar Signature Phacoemulsification System (Abbott Medical Optics) — allow surgeons to remove dense cataracts without building too much heat or using too much ultrasonic energy,” she said. “The Infiniti (Alcon) has a new software program called IP that automatically mixes in traditional longitudinal ultrasound with the torsional phaco to prevent clogging of the tip with dense lenses.”

The new Alcon Ultrachopper tip adds a rotating chopper onto the end of a phaco handpiece to cut through even the densest of lenses with minimal phaco energy.

“They don’t use the side-to-side motion, but the new improvements in all of the machines have made the followability, the cutting ability — all of those have been improved over the last generation of phaco machines,” Dr. Henderson said.

The Ellips FX handpiece combines transversal and lateral motion, Dr. Steinert said.

“You’re not locked into a Kelman tip the way torsional requires to get any benefit. It increases the versatility of that technology and makes it something that any surgeon would be comfortable with,” he said.

The Stellaris and WhiteStar systems incorporate venturi pump technology, which maximizes anterior chamber stability, Dr. Steinert said. Previous phaco platforms only offered peristaltic pump technology.

“AMO has the ability to switch back and forth on the fly between peristaltic and venturi,” Dr. Steinert said. “Some people really do like the venturi fluidics. In that case, they have two companies they can evaluate and choose between. Only the AMO Sovereign WhiteStar offers both pumps.”

Placement of LRIs, toric IOLs

Recent imaging and aberrometry innovations promise to help surgeons place limbal relaxing incisions and toric IOLs more accurately. For example, OSN Cataract Surgery Board Member Robert H. Osher, MD, and Haag-Streit developed improvements to the company’s photographic slit lamp. SMI Photo Systems has unveiled a photographic imaging system that uses iris characteristics to determine the optimal limbal relaxing incision position, Dr. Steinert said.

Carl Zeiss Meditec is currently introducing Callisto Eye, a modular suite of integrated devices. The Callisto array is expected to be available in the U.S. in spring 2012.

The Callisto platform may be used with the IOLMaster 500, the newest iteration of the popular biometry device. The IOLMaster 500 obtains IOL measurements and simultaneously captures images of the eye that are superimposed over real-time images during surgery. The superimposed images help the surgeon position a limbal relaxing incision or toric IOL.

“You don’t have to do anything different. There’s no extra device — it’s all integrated. It’s a very clever and user-friendly approach,” Dr. Steinert said.

Another recent innovation, the ORA intraoperative aberrometer (WaveTec), captures a wavefront measurement of the eye and calculates IOL power and position.

“The software is very clever. … It will actually tell you what to do,” Dr. Steinert said. – by Matt Hasson

• Bonnie An Henderson, MD, can be reached at Ophthalmic Consultants of Boston, 52 Second Ave., Waltham, MA 02451; 781-487-2200; email: bahenderson@eyeboston.com.
• Roger F. Steinert, MD, can be reached at the Gavin Herbert Eye Institute at University of California, Irvine, 118 Med Surge I, Irvine, CA 92697-4375; 949-824-8089; fax: 949-824-4015; email: steinert@uci.edu.
• Disclosures: Dr. Henderson is a consultant for Alcon. Dr. Steinert is a consultant to Abbott Medical Optics.