Today’s phaco machines pave way for future technologies

Surgeons reveal which features they value in phacoemulsifiers.

More flexibility in phacoemulsification machines means better outcomes, according to surgeons interviewed by Ocular Surgery News.

The surgeons we spoke to said they value systems that allow them to change phaco settings for each procedure and every patient.

Yet they are also looking toward the future. They want improved fluidics and a choice of ultrasound or burst modes, as well as decreased energy in the eye – features that will allow cataract surgery through increasingly smaller incisions.

The future, according to these surgeons, is more efficient machines, more reliable outcomes and greater control over every phase of the procedure.

AMO Sovereign

Alessandro Franchini, MD, has been using the Sovereign phaco system with WhiteStar technology for more than 2 years in his Florence, Italy, practice. He said he has been interested in small-incision cataract surgery for more than 10 years and began working with an Er:YAG laser for cataract extraction in 1993, before developing a bimanual technique in 1994.

Dr. Franchini said it is necessary to reconsider the cataract extraction process and adapt it to a narrower incision, performing all phases of the operation through watertight incisions.

“In my opinion, the fundamental point is to avoid the presence of outflow in all phases of the operation [because it] may create dangerous anterior chamber collapse,” he said.

Dr. Franchini said a lowered temperature at the tip is an important aspect of a phaco system. This makes it possible to work without the phaco sleeve through two watertight incisions.

WhiteStar produces rapid bursts of ultrasonic energy between rest periods, allowing the tip to cool and eliminating the need for outflow from the anterior chamber. In standard pulsed phaco, the rest time is not sufficient to adequately cool the tip, leading to a progressive increase in temperature, he said.

Dr. Franchini confirmed the White-Star’s lower temperature increases in an in vitro study, in a closed chamber of 2.5 cc of water under standard conditions.

In the study, the WhiteStar and an Er:YAG laser produced a similar temperature increase of around 2° C to 3° C after 30 seconds, maintaining the temperature under 42° C. He said this is important because corneal changes in wound burns occur at about 45° C.

“This is the first machine with which it is possible to reach what has been the dream of all ophthalmologists working in anterior chamber surgery — to perform the operation through a 1-mm incision in patients with every kind of nuclear hardness in the same amount of time as using standard ultrasound,” he said.

Whatever parameters and techniques are used, Dr. Franchini said, when using the WhiteStar, the effective phaco time is five times less than using a standard pulsed phaco without a decrease in the efficiency of the machine.

“In fact, the use of only transient cavitation (the most efficient part of the cavitation energy), the decrease of the turbulence in the anterior chamber and the improvement in holdability and followability guarantees an efficiency similar to the efficiency guaranteed by a standard phaco machine,” he said. “We have a significant improvement in corneal clarity on the first postoperative day and a significant decrease in the corneal stromal thickening the day after surgery. Furthermore, we have a decrease in endothelial cell density loss that is above all linked to the decreased number of particle impacts generated by the decreased chatter in anterior chamber.”

The newest development from AMO is the Sovereign Compact, which weighs 14 kg, a three-quarter reduction in size. The Compact features a simplified foot pedal and fewer customizable options for a more user-friendly experience, according to the company.

Alcon Legacy, Infiniti

Khiun Tjia, MD, an ophthalmologist in Zwolle, Netherlands, said he switched to Alcon’s Legacy phaco system in 1993 because, at the time, it was the only completely upgradable system.

He said he has stayed with the Legacy because of the latest upgrade to the system, the AdvanTec, a digital ultrasound driver providing more efficient use of ultrasound.

“Not only [is it] more efficient, [but also] more precise, more predictable and more reliable, meaning low power is true low power, which [is] useful … because you do not lose contact with the nuclear material,” he said.

He said a phaco system’s holding force is dependent on vacuum and aspiration as well as repelling forces. “If you can control these repelling forces accurately, that is a useful tool for this kind of efficiency, not only on the low end, but also on the high end, during sculpting,” he said.

With a divide-and-conquer technique, Dr. Tjia said, the Legacy AdvanTec produces true stroke linearity from 0% to 100% power, in contrast with previous drivers or other systems.

“That means I can really attack a nucleus of any kind of hardness up to dark brown or black, on which I was not confident using older systems,” he said.

With harder nuclei, Dr. Tjia said grooving is normally avoided because there is no aspiration flow during occlusion. In these cases, he said, grooving would increase the risk of thermal injury, particularly when a lot of energy is continuously being used.

“Using pre-occlusion mode, when it senses near occlusion, the Legacy will start pulsing. Pulsing during grooving is already one way to avoid excessive heating, but by doing continuous with pre-occlusion mode, you have the best of both worlds because you can have the most efficient, effective high-power settings,” he said.

He added that where he would once need five or six passes, “I now need three, two and sometimes just one because you can go in all the way like in a phaco chop.”

During grooving, Dr. Tjia uses a microflared Kelman 45° tip with 50 mm Hg vacuum pressure and 15 mL/min flow. During quadrant removal, 425 mm Hg vacuum and 50 mL/min flow is used with maximum power of 30% to 40%. With 40% power, even the hardest nuclei are emulsified in a controlled manner, he said.

“In older systems, with harder cataracts, the delivered energy was not always what you asked for. With the digital ultrasound driver, you get what you want, which has made a tremendous difference in ultrasound control,” he said.

Alcon’s latest system, the Infiniti Vision System, has many differences from its predecessor the Legacy, particularly in respect to fluidics, according to one user.

Richard B. Packard, MD, FRCS, FRCOphth, of Berkshire, England, a clinical investigator of several phaco systems, said the Infiniti exceeds the Legacy. Although the ultrasound driver is the same, power modulation capabilities are more extensive on the newer unit, he said.

Dr. Packard said he performed about 25 cases using a prototype of the Infiniti system in clinical investigations. The Infiniti has been on the market since April.

He said the system has a micropulse option: short, spaced bursts of ultrasound energy and rest, which can be adjusted by the surgeon to provide efficient nuclear breakup without excessive heating. The phaco power can be adjusted in this mode in a linear manner similar to conventional phaco, he said.

Dr. Packard stressed that the Infiniti is not an upgrade to the Legacy. Rather, it is a completely different machine. The pump mechanism has had all compressible tubing removed, eliminating almost all of the compressibility, he said.

“When you get an occlusion break, you do not get surge. That’s because of the tubing … and because of the cartridge, which is totally rigid so nothing can collapse inside of it,” he said.

Since there is almost no buildup of energy in the system, Dr. Packard said, higher vacuum and flow levels can be used, depending on the tip. A 19-gauge tip would use lower, flatter vacuum than the 21-gauge microtip, although up to 600 mm Hg or 700 mm Hg can be safely used, he said.

“The first time I used this machine in the lab … we really cranked it up. It was extraordinary to see how stable the chambers were,” Dr. Packard said. “Of course, what it also means is that everything happens very quickly. Although the chamber is stable, you may not want to use those settings. But it does mean that whatever settings you do use, whatever settings a surgeon chooses to use, what they do will be dramatically safer and more consistent.”

Dr. Packard said the Infiniti also has a feature called AquaLase, which can break up a nucleus using pulsed water jets. He said AquaLase is effective for soft to medium cataracts, but does not work as well as ultrasound for harder cataracts.

“As we move towards an era where there will be more refractive lens exchanges, using a system like this, where it makes it almost impossible to break the posterior capsule, gives you an added level of safety in combination with the great fluidics,” he said.

Dr. Packard said the Infiniti also features a “power wash” mode, allowing the AquaLase tip to be maneuvered right up to the capsule to clean the capsule, a feature he said could be particularly useful for bimanual phaco.

AOI Horizon

While American Optisurgical Inc. (AOI) is just beginning to market its Horizon phaco machine in the United States, the company is touting it as a cost-effective system with high-end features.

The portable Horizon is already being used by surgeons worldwide, according to Cam Cameron, AOI president. The company launched the product at the 2002 meeting of the American Society of Cataract and Refractive Surgery.

The Horizon offers features such as burst modes, a programmable footswitch, six programmable modes and one of the lightest all-titanium handpieces on the market, according to product information.

AOI designed the system to be fully controllable with a personal digital assistant such as a Palm Pilot, which acts like a remote control and provides increased functionality, according to the company. Using an infrared or wired remote control is also an option for surgeons.

The 40 kHz, four-crystal, piezoelectric handpiece works with multimodular phaco settings. I&A mode uses a peristaltic, low-pulsation aspiration pump. Vitrectomy is performed with a pneumatic guillotine cutter that creates 50 to 700 cuts per minute.

Other features include a large LCD touch screen and the option of easy loading disposable and reusable tubing, according to the company.

A.R.C. Laser Dodick PhotoLysis

One of the first machines to offer an alternative to ultrasound phaco is the Dodick Laser PhotoLysis from A.R.C. Laser. The system employs a Nd:YAG laser to break up and remove the crystalline lens. It works best on softer cataracts in the range of 1+ to 3+, the machine’s inventor, Jack Dodick, MD, told Ocular Surgery News in an interview last year.

“It is impossible to produce a corneal-scleral burn with this laser apparatus,” he said.

Anastasios John Kanellopoulos, MD, led a study of the Dodick PhotoLysis, in which cataract extractions were performed on 1,000 eyes at 12 international sites. The study, published in Ophthalmology, reported a low incidence of complications at 1.8%.

Sixteen eyes experienced intraoperative capsular rupture and two had intraoperative hyphema, according to the study. Since most of the complications occurred in the investigators’ early patients, the authors concluded that there is a learning curve associated with this machine.

Dr. Kanellopoulos and colleagues also found that mean operative times were consistent: 2.5 minutes for cataract densities of 1+, 4.8 minutes for 2+ and 9.8 minutes for 3+. They measured mean intraocular energy at 5.65 J per case.

Dr. Dodick noted that vacuum pressure and flow rate with the Dodick system are consistent with ultrasound systems. He added, however, that surgeons must modify part of their procedure to compensate for the inability of the laser to impale the nucleus. The surgeon can either use a nuclear chop method with two specially designed hooks, or “back-crack” it with the infusion instrument while lifting it out of the capsular bag.

Bausch & Lomb Millennium

Graham Barrett, FRACS, FRACO, said he switched to the Bausch & Lomb Millennium Phaco System 6 years ago. He became interested in it because it combines a venturi pump with simultaneous dual linear control of ultrasound and aspiration.

“I felt that the system offered the potential for improved efficiency and control,” he said. “A venturi system is more responsive than a peristaltic system and therefore more suitable for surgeon control in a dual linear system.

Dr. Barrett said the Millennium technology has focused on fluidics, featuring accessories such as the Micro-Flow phaco needle, which he said reduces the likelihood of incision burns while allowing use of a fully sealed 2.6-mm incision.

“The needle, combined with the 28 kHz handpiece, is powerful and efficient, capable of dealing with extremely hard nuclei using relatively low power settings,” Dr. Barrett said.

Dr. Barrett said the ability to control vacuum is helpful when using the phaco axe technique, his preferred surgical technique, similar to a quick-chop.

Typically, vacuum levels that are required for embedding the phaco tip and cracking the nucleus are different from those needed for removing fragments. However, with the Millennium system and Micro-Flow needle, Dr. Barrett said he can use the same settings throughout surgery — 70 mm Hg to 140 mm Hg — controlled in a linear fashion.

“The need to be able to control vacuum in a linear fashion is no different than the need to control ultrasonic energy in a linear fashion for optimum outcomes in phacoemulsification,” he said.

The software controlling the ultrasound on the Millennium system has pulse and burst mode options. But Dr. Barrett said this feature is less important to him because the Micro-Flow needle allows so-called “cold” phaco.

“My personal experience is that pulse may be helpful in extremely hard nuclei. But generally, the intermittent nature of the application of ultrasound in both pulse and burst is somewhat less efficient and, in my hands, slows down the removal of material to some extent,” he said.

Dr. Barrett added that the system is modular, allowing upgrades to be added, such as the Concentrix pump and enhanced vitrectomy modules.

“The economics of having a single multiuser machine for anterior and posterior segment surgeons is extremely attractive. … Similarly, the availability of the Concentrix pump, which can operate in a flow-priority manner similar to a peristaltic system, is helpful in an environment catering to different surgeons,” he said.

Paradigm’s SIStem

Enrique Pfeiffer, MD, said three features make a great phaco machine: fluidics, aspiration and surge. “[They’re] probably the most important part of the dynamics of the surgery,” he said.

The fluidics of the SIStem (Solutions in Surgery) from Paradigm Medical Industries incorporates improved hydrodynamics with a mini-peristaltic I&A pump, according to product information.

Dr. Pfeiffer, of Barcelona, Spain, said that the handpiece and ultrasound delivery capabilities of the SIStem are comparable with those available with better-known machines on the market. In addition, Dr. Pfeiffer said the system is reliable and complications are rare.

What distinguishes the SIStem, though, is its excellent fluidics, he said. “Fluidics is one of the strongest points of the system, the way that the system reacts on the footswitch,” Dr. Pfeiffer said.

He noted, however, that the SIStem is still using software that is 2 years old. It has not been upgraded, for instance, to feature some of the cool-tip algorithms used by other companies, he said.

Nevertheless, he said the machine’s fluidics, aspiration and surge make it competitive with other available systems. “The equipment remains, in the actual configuration, a valuable system, and a very valid system to practice cataract [surgery] in the market,” he said.

STAAR Surgical SonicWave

Harry B. Grabow, MD, of Sarasota, Fla., said his choice of machine, the SonicWave from STAAR Surgical, combines safety and efficiency.

“First of all, I find that the fluidics are extremely sensitive and responsive to my foot pedal commands, more so than any other machine that I’ve worked with,” he said. “So that when I am working with aspiration … whether it’s with phaco or I&A, I get an excellent response with the machine and the tubing to my foot pedal commands.”

STAAR Surgical also offers a unique phaco tip design, he said. “I routinely use the Gravlee Safety Bevel Tip, and this tip tends to be friendlier to the cornea as well as more efficient than other tips in holding and aspirating nuclear material,” Dr. Grabow said.

“Thirdly, I like the sonic mode availability with this machine,” he said, “which allows the surgeon to perform unsleeved phaco, which may be the way we perform phaco in the future, allowing us to go down to incisions in the range of 1.5 mm.”

Dr. Grabow said he uses ultrasound mode to perform chopping maneuvers and to remove the hard cores in nuclei of greater than 2+ density. He uses sonic mode on softer nuclei and to remove the epinucleus in all cases.

The SonicWave also allows surgeons to employ one of three types of tubing on a case-by-case basis, he added. The standard straight tubing works well on softer nuclei (1+ or 2+) and low vacuum cases, Dr. Grabow said. He added that he chooses either the “Hi Vac” coiled aspiration tubing or the so-called “Cruise Control” chamber to tackle harder nuclei that require higher vacuum settings.

“The different types of tubing help to produce a more stable chamber to reduce surge when the vacuum is set high,” he said.

“It’s extremely efficient,” Dr. Grabow said. “The corneas look clearer than I have found with other machines, and the availability of going from sonic to ultrasound, back and forth, with foot pedal control of the mode, along the Gravlee Safety Bevel tip, have made this my choice of machines.”

Dr. Grabow added that the machine has digital capabilities, such as the ability to make digital recordings of each procedure, and a port that enables those recordings to be transmitted through the Internet in real time.

Surgical Design’s Ocusystem

For Jack A. Singer, MD, of Randolph, Vt., the best machine is one that maintains constant intraocular pressure, even in worst-case scenarios.

Dr. Singer noted that even the best surgeons cannot prevent capsular tears in every case. The Ocusystem A.R.T. Advantage has “super surge prevention” to prevent vitreous prolapse, he said.

“So that nine out of 10 times of capsule tears – which occurs in one out of 150 cases, I’d say – nine out of 10 of those have no vitreous prolapse, no vitreous loss. The vitreous face remains intact and it doesn’t come forward because the intraocular pressure is maintained,” he said. “And that allows me to do a posterior capsulorrhexis and put the lens in the capsular bag.”

Surge prevention is more responsive and steadier than in other models, Dr. Singer noted. “The outcomes are excellent with a very rare incidence of complications such as posterior capsular rupture and zonular dehiscence,” he said.

The Ocusystem features simultaneous linear control of power, flow and vacuum. “That makes the use of high vacuum safer, because when trilinear is used, the high vacuum – up to 500 mm Hg – is used automatically only when there is a dense nucleus that requires higher ultrasound power to break the occlusion,” he said. “I call it high-vac on demand.”

The Ocusystem also has an automated free-flow option, allowing surgeons to choose between using a vacuum or free-flow valve, in which fluid bypasses the pump as it flows through the infusion and into the eye, Dr. Singer said.

The free-flow option allows safer cortical and capsular cleaning, according to Dr. Singer, and the pump can be reactivated with the foot pedal when needed. “It’s always safer to use that,” he said.

At 50 kHz, the phaco handpiece is also one of the smallest and lightest on the market, making it easy to switch hands during the procedure, according to Dr. Singer.

For Your Information:

• Graham Barrett, FRACS, FRACO, can be reached at 2 Verdun St, Nedlands WA 6009, Australia; +(618) 93-810-872; fax: +(618) 93-821-171; e-mail: barrett@cyllene.uwa.edu.au.
• Khiun Tjia, MD, can be reached at Heerderweg 14, 8161 BM EPE, Zwolle, Netherlands; fax: +(31) 578-629-940; e-mail: k.tjia@isala.nl. Dr. Tjia has no direct financial interest in the products mentioned in this article.
• Richard B. Packard, MD, FRCS, FRCOphth, can be reached at 12 Clarence Rd, Windsor, Berkshire SL4 5AG, England; +(44) 1753-829204; fax: +(44) 1753-831185; e-mail: eyequack@vossnet.co.uk.
• Dr. Packard is a consultant for Alcon on the Infiniti Vision System.
• Alessandro Franchini, MD, can be reached at the Azienda Ospedaliera Careggi, Viale Pieraccinc, 17, 50139 Firenze, Italy; +(39) 55-42-77-550; fax: +(39) 55-42-22-679; e-mail: alessandrofranchini@yahoo.it.
• Dr. Franchini has no direct financial interest in the products mentioned in this article. He is a paid consultant for Advanced Medical Optics.
• Harry B. Grabow, MD, can be reached at 3920 Bee Ridge Rd, Building F, Suite A, Sarasota, FL 34233; (941) 921-7744; fax: (941) 921-3783; e-mail: harry@grabow.com.
• Dr. Grabow has no direct financial interest in the products mentioned in this article.
• Jack A. Singer, MD, can be reached at Singer Eye Center, 45 South Main St, Randolph, VT 05060; (802) 728-9993; fax: (802) 705-1002; e-mail: jack@singereye.com.
• Dr. Singer is a paid consultant for Surgical Design.
• Enrique Pfeiffer, MD, can be reached at Lagespa #15, Barcelona 08017 Spain; +(34) 93-206-0638; e-mail: epfeiffer@paradigm-medical.com. Dr. Pfeiffer is a paid consultant for Paradigm Medical.

• Advanced Medical Optics, makers of WhiteStar Technology for the Sovereign System, can be reached at 1700 E St. Andrews Pl, Santa Ana, CA 92799; (800) 449-3060; fax: (866) 872-5635; Web site: www.amo-inc.com.
• Alcon, makers of the Legacy and Infiniti phaco systems, can be reached at 6201 South Freeway, Fort Worth, TX 76134; (817) 293-0450; fax: (817) 568-6142; Web site: www.alcon.com.
• American Optisurgical Inc., makers of the Horizon, can be reached at 25501 Arctic Ocean, Lake Forest, CA 92630; (949) 580-1266; fax: (949) 580-1270; Web site: www.optisurgical.com.
• ARC Laser Corporation, makers of the Dodick Photolysis, can be reached at Von-Brentano-Str. 31, 90542 Eckental, Germany; +(49) 9126-2598-0; fax: +(49) 9126-2598-29; Web site: www.arclaser.de.
• Bausch & Lomb, makers of the Millennium phaco system, can be reached at 1400 N Goodman St, Rochester, NY 14609; (585) 338-5212; fax: (585) 338-0898; Web site: www.bausch.com.
• Paradigm Medical Industries, makers of the SIStem, can be reached at 2355 South 1070 West, Salt Lake City, UT 84119; (801) 977-8970; fax: (801) 977-9128; Web site: www.paradigm-medical.com.
• STAAR Surgical, makers of the SonicWave, can be reached at 1911 Walker Ave, Monrovia, CA 91016; (626) 303-7902; fax: (626) 358-9187; Web site: www.staar.com.
• Surgical Design, makers of the Ocusystem Advantage, can be reached at 4253 21st St, Long Island City, NY 11101; (800) 458-4344; fax: (718) 786-2139; e-mail: info@surgical.com.

Reference:

• Kanellopoulos AJ. A prospective clinical evaluation of 1000 consecutive laser cataract procedures using the Dodick photolysis Nd:YAG system. Ophthalmology. 2001;108:649-654.