Less energy in the eye is trend among phaco units

Several units allow a bimanual approach through smaller phaco incisions.

If we can sum up the most recent advances in phacoemulsification technology in one phrase, it is this: less energy in the eye. Whether through microsecond-long cycles of burst and rest, use of sonic instead of ultrasonic energy or use of a laser, manufacturers have devised novel methods of reducing the amount of energy, and therefore heat, entering the eye during cataract surgery.

If there is less heat, there is less need for a sleeve around the phaco tip, and thus incision size can be reduced. Surgeons are finding that a bimanual approach to phaco can allow operating through two 1.2-mm incisions, improving chamber stability and safety and reducing patients’ postop discomfort.

But energy level is not the only feature a surgeon considers in choosing a phaco machine. Convenience, portability, even price enter into the equation. Manufacturers offer instruments with a dizzying variety of options to address the needs of virtually any surgeon.

“The choice of a phaco system is really a complex issue,” said I. Howard Fine, MD, of Eugene, Ore.

Dr. Fine should know. He has experience with a large number of phaco machines as part of his ongoing investigation of ophthalmic technology.

“Because I’ve been working with a number of companies regarding investigations, I use maybe five different systems each day I operate. I absolutely love all the machines. I’ve been thrilled to be a part of 20 years of incremental improvement in phaco technology,” he said.

For this article we interviewed Dr. Fine and other leading surgeons to learn what some of the best phacoemulsifiers on the market today have to offer. The trend toward less energy use was a common theme, though the problem is approached in a different way by each company. Fluidics and improved stability of the anterior chamber were also common themes.

Following is our review of current phaco technology.

Alcon’s Legacy and AdvanTec

The Series 20000 Legacy, manufactured by Alcon, is “a spectacular machine,” Dr. Fine said. “It has excellent control and fluidics.”

The Legacy features linear control of ultrasonic power, producing a constant, smooth response in high and low power settings, according to Alcon literature. Its controlled fluidics can offer rapid flow, vacuum and venting, with microprocessors to control the fluidics at occlusion breaks.

The system includes a range of handpieces and tip configurations suited to numerous surgical techniques. Surgeons can use the Mackool, Micro-tip MV, ABS Technology, Flared ABS Technology or Mackool Flared ABS Technology tips, depending on their preferences.

A user-friendly interface system is programmable for retrieval of up to 96 memory options, which allow for multiple surgeons to set their own surgical parameters on one machine. A touch screen and electronic voice confirmation system enhance simplicity and safety by allowing surgeons to concentrate solely on the patient.

Dr. Fine said his use of the Legacy has resulted in clear corneas on postop day 1 in 90% of his patients, with 70% of them reaching an uncorrected visual acuity of 20/40 on day 1. However, he noted, the performance of the Legacy is “enormously improved” with the addition of AdvanTec hardware and software and NeoSoniX oscillation handpieces.

“The upgrades offer significant improvements. I’ve had great results — an 85% reduction in phaco time with lower energy by 50%,” Dr. Fine said.

The upgraded technology offers advantages over the basic system. According to Dr. Fine, the AdvanTec hardware and software reduces the amount of energy entering the eye by allowing the Legacy to deliver bursts of energy — in short or long pulses — with variable periods of rest.

The software allows customized settings and automated modes of chopping that reduce chatter and energy. This reduction in energy allows harder cataracts to be tackled with greater ease. The NeoSoniX handpiece oscillations reposition the lens tissue on the tip, swiftly breaking up the nuclear fragments. According to Dr. Fine, the handpiece is versatile and eliminates the need for surgeons to exchange tips and irrigation sleeves.

“Therefore, phaco time is reduced and efficiency is improved,” he said.

The lower energy also seems to improve visual outcomes.

“In my patients, the UCVA threshold of 20/40 on day 1 has increased from 70% to 96%, while clear corneas on day 1 have increased from 90% to 98%,” Dr. Fine said. “AdvanTec technology has been an excellent addition to the Legacy.”

AMO’s Sovereign and WhiteStar

Another phacoemulsification system that has been improved by new technology is the Sovereign system from Advanced Medical Optics (AMO). The traditional Sovereign system is noted for its ability to sense pressure variations at the phaco tip and respond quickly to remove debris and eliminate post-occlusion surges.

“The system is able to respond instantaneously because of the highly developed computer-controlled fluidics, now combined with the exquisite WhiteStar ultrasonics,” said Roger Steinert, MD, of Boston.

The Sovereign’s vacuum level ranges from 0 to 500 mm Hg in 5-mm Hg increments. Pump flow rates range from 10 to 40 cc/min in 2-cc increments.

To ensure sensor accuracy, the Sovereign continuously purges air from the aspiration system. This eliminates one of the most common sources of vacuum surge, Dr. Steinert said.

The AMO WhiteStar technology, which is available for the Sovereign, enhances the safety and efficacy of the device by modulating the traditional ultrasound flow into microbursts of energy followed by rests when no power is generated, allowing the system to run cooler.

“As a result of this technology, research has shown that burns are a thing of the past,” said Richard B. Packard, MD, FRCS, at the meeting of the American Society of Cataract and Refractive Surgery in Philadelphia.

The WhiteStar technology enables the Sovereign to alternate between ultrasound bursts and rests as brief as 20 msec. The modulation reduces the amount of heat energy generated and cools the tip of the phaco handpiece.

“This effective method of destroying the cataract with minimal heat is what I call ‘cold’ phaco,” Dr. Fine said. In his experience with this system, Dr. Fine said he has had satisfactory results.

“The Sovereign with WhiteStar in the burst mode offers great results, but I find it must be set at the highest setting,” he added. In his practice, he noted that the percentage of clear corneas at 1 day postop rose from 86% with the Sovereign to 100% with the Sovereign with WhiteStar.

“In my studies, UCVA of 20/40 within 1 day of surgery rose from 81% to 94% of patients,” Dr. Fine said.

Likewise, Dr. Steinert reported positive results with this “cold” phacoemulsification system. He said the WhiteStar technology allows him to use the Sovereign phaco tip without an irrigation sleeve, without fear of wound burns. The sleeveless phaco tip allows a reduced incision size. Dr. Steinert has participated in studies using the sleeveless tip through a 1.2-mm incision. He said he has seen great results.

“Now we are just waiting for IOLs to catch up to this smaller wound size,” Dr. Steinert said.

Bausch & Lomb’s Millennium

The Millennium Microsurgical System from Bausch & Lomb has three notable features: its Dual Linear Control, Concentrix fluidics control technology and micro-phaco burst capabilities.

“The dual linear pedal control mechanism is fairly unique in the marketplace,” said Barry Seibel, MD, of Los Angeles. “It allows the surgeon to simultaneously have linear control of both fluidics and ultrasound, so he can choose the combination of the two that makes most sense according to what is seen through the operating microscope.”

Dr. Seibel cited several advantages to using the Millennium system, its modularity being one of them. The ability to replace parts as more advanced features become available keeps the system from growing obsolete. The system can also use more than one pump, depending on the pump preferences of the individual surgeon in centers with more than one surgeon.

“Some surgeons may prefer one pump type, another group may prefer another. Because of the modularity, they can change pumps or they can have both in the same machine, which I think is a big benefit,” he said.

The Concentrix feature gives surgeons the ability to switch from a vacuum pump mode to flow pump mode with the press of a button. He said the system can be tailored to emulate almost any machine the surgeon is used to using.

“[The system] can be run like a vacuum pump or a venturi pump. Some surgeons prefer a vacuum pump for phaco, and many surgeons, even the ones who prefer peristaltic or flow pumps for most of phaco, like a vacuum pump for cortical cleanup,” Dr. Seibel said.

The new Millennium system includes enhanced ultrasonic drivers, giving more control of the ultrasound with pulse and micro-phaco burst modes.

“It’s always had the pulse mode, but now you just have more elaborate control of that, as well as micro phaco burst mode for those surgeons that prefer that method,” Dr. Seibel said.

He said Bausch & Lomb is currently developing Avantix, a different mode of emulsification using a vortex and impeller technology instead of ultrasound. When that module becomes available, it too can be fit into the Millennium.

Dr. Fine, who has investigated the Avantix system, said it has worked very well in his microincision investigational studies.

STAAR Surgical’s SonicWave

STAAR Surgical’s SonicWave phacoemulsification system takes a different approach to lens fragmentation. The SonicWave uses sonic energy in the range of 40 Hz to 400 Hz in addition to the 40,000 Hz range that ultrasonic phaco machines generally employ.

The lower energy generally produces less heat, reducing the risk of corneal burns. The SonicWave can be switched between sonic and ultrasonic modes with a foot pedal.

According to the company, the SonicWave allows excellent chamber stability and surge protection. It is possible to emulsify all grades of cataracts, although it can take longer for dense, 4+ cataracts in sonic mode.

Dr. Fine, who also has experience using this system, noted there is no negative impact on clear corneas using the sonic setting compared to the ultrasonic settings. In his studies, 96% of his patients had clear corneas on postop day 1. Seventy-nine percent of his patients achieved a UCVA of 20/40 at day 1 postop.

The SonicWave also employs another recent addition to STAAR Surgical’s product line, the UltraVac coiled tubing.

STAAR’s UltraVac coiled tubing is designed to stabilize the anterior chamber and to prevent post-occlusion surge, which can cause anterior chambers to dimple and collapse.

The tubing causes a change in fluid direction within the tubing itself to create a barrier to occlusion rush. At low fluid flow rates, the tubing acts similarly to other standard tubings. However, at rates above 50 cc/min, the coils create a turbulent flow within the tubing to prevent occlusion rush or surge.

Dodick ARC PhotoLysis

Another approach to the less-energy, less-heat trend in cataract surgery is found in the Dodick ARC PhotoLysis phacoemulsification system (ARC Laser Corporation). This system uses an Nd:YAG laser instead of ultrasound to break up a cataractous lens. According to Jack Dodick, MD, of New York, inventor of the system, the laser system has the advantage of producing no clinically significant heat.

“It is impossible to produce a corneal-scleral burn with this laser apparatus,” Dr. Dodick said in an interview. “Also, the infusion can be separated from the laser emulsifying probe, thus making it possible to perform the operation through two 1.2-mm incisions.”

Dr. Dodick noted the average time to remove a cataract of 1+ to 3+ nuclear sclerosis is equivalent to ultrasound phaco. He said this is a common misunderstanding regarding the capabilities of laser systems.

“Contrary to previous beliefs regarding lasers, this system is not slow. Of course, this does not apply to harder nuclei, 4+ density, which at the present time can not be adequately addressed with this system,” Dr. Dodick said.

“The 1+ to 2+ [cataract procedures] are slightly shorter in time,” he said. “The reason for this is that the bimanual probes inserted through the two incisions not only can lyse and remove the nucleus, but can stay inside the eye at the end of nucleus removal to act as bimanual cortical cleanup instruments.”

Vacuum pressure and flow rates are similar to those of ultrasound phaco systems, and the procedure can be performed under relatively high vacuum levels of 250 mm Hg to 300 mm Hg.

The Dodick laser system does, however, require the surgeon to use special surgical techniques. According to Dr. Dodick, the laser system cannot impale the lens like an ultrasound system, “so new surgical techniques to circumvent this problem were devised.”

One technique requires the lens to be sliced using a nuclear chop method employing two specially designed hooks.

“This basically sections the cataract into three pieces that can now be lifted out of the capsular bag with the laser probe, lysed and then aspirated,” Dr. Dodick said.

A second approach involves lifting the lens out of the capsular bag with the laser probe and “back-cracking” it with the infusion instrument, he said.

“This also will section the lens into multiple segments, which then can be lysed and aspirated out of the eye,” Dr. Dodick said.

Dr. Dodick said there is a learning curve involved with these methods, “surprisingly not for the laser aspiration of the cataract particles, but the learning curve is in the technique of either slicing the nucleus prior to lysing or back-cracking the nucleus prior to lysing,” Dr. Dodick said.

Paradigm’s SIStem

The SIStem (Solutions In Surgery) Phacoemulsification System by Paradigm is comparable to other microsurgical systems and is available at a lower cost, said Luther Fry, MD, who practices in Garden City, Kan. The SIStem is his first choice in phaco machines, mainly because it is a more affordable system.

“It works just as well, but not better, than the other high-end units and is more cost-effective because of reusable tubing,” he said. “The system is fairly user-friendly with a good LCD screen and remote control of functions similar to other units.”

The Paradigm SIStem employs a mini-peristaltic pump and advanced hydrodynamics, which Dr. Fry said allow good chamber stability.

“I particularly like the VRT feature, which allows parameters to change and increase flow and vacuum during a case once occlusion is achieved. This allows for very efficient attraction of peripheral wedges of nucleus to the center for emulsification,” he said.

Another attractive feature is the low incidence of thermal burn, something that Dr. Fry said he has experienced with other machines.

“This has not happened with the SIStem, even if I ‘floorboard’ it for longer than I should,” he said.

Dr. Fry cited no surgical complications stemming from the system. He said there are some tradeoffs when using a machine from a relatively small manufacturer.

When service has been required, he said, “They have been good about sending backup units overnight. We also have an additional unit so breakdowns haven’t been disruptive,” he said.

Surgical Design Ocusystem A.R.T. Advantage

According to Jack Singer, MD, the most important feature of any phaco system is the system’s surge prevention capability, “its ability to maintain a constant intraocular pressure while working within the eye.”

Dr. Singer, of Randolph, Vt., said that in his experience the Ocusystem A.R.T. Advantage from Surgical Design does this better than other available systems.

“The most important thing is the ability to maintain the intraocular pressure, so you don’t get mini collapses due to post-occlusion fluid surges. I believe Surgical Design has the best surge prevention,” Dr. Singer said.

A.R.T. stands for Adjustable Rise Time. An in-line IOP transducer sends information to a microprocessor to ensure automatic surge protection.

According to Dr. Singer, Surgical Design has included automatic surge prevention in its systems since the early 1980s. He said, however, that the Ocusystem A.R.T. Advantage has improved upon the surge prevention capability compared to earlier Ocusystem models.

“It’s more responsive, allowing higher flow rates of up to 50 cc/min and up to 500 mm Hg vacuum. And you still have a very stable anterior chamber to work in,” Dr. Singer said.

“You really notice it while doing I&A. With most systems, the chambers bounce, the capsules bounce. But with the Ocusystem, the I&A allows a very stable chamber. With this system you don’t have to compromise anything. You can go full throttle using 500 mm Hg and 50 cc of flow and still work safely,” he said.

According to company information, Ocusystem’s Tri-linear phaco enables any combination of linear control of power, flow and vacuum for more efficient use of system fluidics and ultrasonics. The system also has expanded memory capabilities that allows the storage of up to 3,200 auto settings.

Another advantage of the Ocusystem, Dr. Singer said, is that its high flow capability helps to prevent wound burns “because you have more flow cooling the tip.”

“It simulates a venturi system and gives you excellent followability,” he said.

AOI’s Portable Horizon

A unit that has been attracting interest for different reasons is the Horizon phacoemulsification system from American Optisurgical Inc. (AOI).

The recently FDA-approved Horizon — a lightweight and portable phaco unit — was introduced at this year’s ASCRS meeting. According to AOI, the Horizon contains features of higher-end phacoemulsification machines for a fraction of the price.

“The Horizon offers high-tech features for a great value,” said Harish Kodial, MD, of India.

Currently, the Horizon is being used primarily in India, Korea and China. Plans are in the works to release the portable phacoemulsification system commercially throughout the United States within the next year.

According to AOI, the Horizon offers complete anterior cataract surgery functions, along with a vitrectomy option that features a pneumatic guillotine cutter. It also includes multi-modulation and burst modes, is fully programmable and is all activated by a large touch panel screen.

The 20-pound unit has I&A functions and “vents as well as refluxes” to the bottle. It uses a peristaltic, low pulsation aspiration pump that has noninvasive Real-Time-Vacuum-Sensing that provides continuous calibration of vacuum.

The phacoemulsification handpiece is a lightweight, all-titanium, four-crystal, 40 kHz design.

“The handpiece is very efficient. It can cut and break a grade-4 cataract with minimal effort,” Dr. Kodial said.

According to Dr. Kodial, the high-power capabilities and lightweight features make the system ideal for situations requiring portability. Surgeons who travel to rural areas or to developing countries can perform surgery easily with a universal input power supply, simple loading features and the disposable or reusable tubing cartridges.

According to AOI, reusable tubing cartridges protect against cross-contamination of bacteria to ensure a safe and clean procedure, whether surgeons are performing surgery in the operating room or in the brush.

For Your Information:

• I. Howard Fine, MD, can be reached at 1550 Oak St., Suite 5, Eugene, OR 97401; (541) 687-2110; fax: (541) 484-3883; e-mail: hfine@finemd.com; Web site: www.finemd.com. Dr. Fine has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
• Roger F. Steinert, MD, can be reached at Ophthalmic Consultants of Boston, 50 Standiford St., Suite 600, Boston, MA 02114; (617) 367-4800; fax: (617) 573-4912. Dr. Steinert has no direct financial interest in any product mentioned in this article. He is a paid consultant for Advanced Medical Optics.
• Richard B. Packard, MD, FRCS, can be reached at HRH Princess Christians Hospital, 12 Clarence Road, Windsor, England SL45AG; (44) 175-382-92204; fax: (44) 175-38-31-185; e-mail: eyequack@vossnet.co.uk. Dr. Packard has no direct financial interest in any product mentioned in this article. He is a paid consultant for Advanced Medical Optics.
• Barry Seibel, MD, can be reached at 10921 Wilshire Blvd., Suite 900, Los Angeles, CA 90024; (310) 208-3937; fax: (310) 230-2901. Ocular Surgery News was unable to confirm whether Dr. Seibel has a direct financial interest in any products mentioned in this article or if he is a paid consultant for any companies mentioned.
• Jack Dodick, MD, may be reached at 535 Park Ave., New York, NY 10021; (212) 288-7638; fax: (212) 832-0640; e-mail: jackdodick@aol.com. Dr. Dodick has a financial interest in the Dodick ARC Photolysis system.
• Luther Fry, MD, can be reached at 310 Walnut St., Suite 101, Garden City, KS 67846-5500; (620) 275-7248; fax: (620) 275-5262; e-mail: lufry@odsgc.net; Web site: www.fryeyemd.org/fry. Dr. Fry has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
• Jack Singer, MD, can be reached at 40 S. Main St., Randolph, VT 05060; (802) 728-2460; fax: (802) 728-3407; e-mail: jack.a.singer@hitchcock.org; Web site: www.eyesurgery.yourmd.com/singer. Dr. Singer has no direct financial interest in the products mentioned in this article. He is a paid consultant for Surgical Design Corp.
• Harish Kodial, MD, can be reached at Grant Rd. West, Mumbai, India 400 007; (91) 22-387-8025. Dr. Kodial has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

• Alcon can be reached at 6201 South Freeway, Fort Worth, TX 76134-2099; (817) 551-4734; fax: (817) 568-7116.
• Advanced Medical Optics can be reached at 1700 E. St. Andrews Place, P.O. Box 25162, Santa Ana, CA 92799-5162; (800) 449-3060; fax: (866) 872-5635; Web site: www.amo-inc.com.
• Bausch & Lomb can be reached at 180 East Via Verde Drive, San Dimas, CA 91773; (800) 338-2020; fax: (800) 362-7006.
• STAAR Surgical can be reached at 1911Walker Ave., Monrovia, CA 91016; (626) 303-7902; fax: (626) 930-1424.
• ARC Laser can be reached at 2417 South 3850 West, Salt Lake City, UT 84120; (800) 500-2979; fax: (801) 972-5251; e-mail: medical@amlaser.com; Web site: www.amlaser.com.
• Paradigm Medical can be reached at 2355 South 1070 West, Salt Lake City, UT 84119; (813) 265-6622; fax: (813) 265-2794; e-mail: mskmhand@aol.com; Web site: www.paradigm-medical.com.
• Surgical Design can be reached at 4253 21st St., Long Island City, NY 11101; (718) 392-5022; fax: (718) 786-2139; e-mail: info@surgical.com.
• American Optisurgical Inc. can be reached at 25501 Arctic Ocean, Lake Forest, CA 92630; (949) 580-1266; fax: 949-580-1270; e-mail: mericle@optisurgical.com.