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Active pressurization another step in advancement of phaco procedure
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Phacoemulsification is the preferred method of cataract removal in all advanced countries. The first machine commercialized was the Cavitron 6000 in about 1966. Phaco surgeons were limited to a handful in the United States only at that time, all personally trained by Charles Kelman, MD, usually in a course in New York City. Early adopters included Robert Sinskey, MD, and Richard Kratz, MD, of Santa Monica, Calif., who under Kelman’s guidance created a second training course in California.
To say that phacoemulsification was controversial would be understating the fierce groundswell of opposition that the innovators and early adopters of this technology faced. I completed my residency at the University of Minnesota in 1977, and our department of ophthalmology had a Kelman Cavitron model 7000 phaco machine, but it was never utilized, except as a table for storing equipment in the university OR suite closet. The early surgeons who tried the technology without significant training and practice usually found the learning curve too steep and the complications encountered too great to continue.
In my fellowship year with our chairman’s approval, I worked with an entrepreneurial and somewhat controversial Minnesota ophthalmologist, David Chizek, MD, on an animal project investigating phaco and its impact on the corneal endothelium in the rabbit and cat. This gave me the unusual opportunity to do many cases in the laboratory and better understand the technology and technique challenges. This led to my deciding to perform a second 6-month fellowship after the first in cornea and external disease with phaco and posterior chamber lens pioneer William S. Harris, MD, in Dallas. Dr. Harris in 1978 performed all his cataract surgery with the patient under general anesthesia, operating 2 full days a week with a high-volume practice, which allowed him to delegate significant responsibility to his fellows in a relaxed and controlled environment. I later joined him as an associate for another 2 years, allowing me to perform nearly 1,000 procedures under his guidance, before returning to join the faculty at the University of Minnesota.
In the late 1970s, the majority of U.S. surgeons were performing intracapsular cataract extraction and, when implanting an IOL, utilizing an iris clip or anterior chamber IOL. A brave few, at that time less than 1% of surgeons, were pioneering phaco and posterior chamber IOLs. I had the extraordinary good fortune to be welcomed into their friendship and began a long journey of special interest in the phacoemulsification procedure and the technology and technique evolution to make it safer and more effective.
In the 1990s, working with Storz Instrument, I helped develop the Storz Premiere, which was the first U.S. phaco machine to offer “active” pressurization, with a pump-driven forced infusion of fluid, which allowed the surgeon to set infusion at a specific IOP rather than use gravity feed with lowering or elevating the balanced salt solution bottle on a pole. I rapidly adopted this option, but at the time it was rarely utilized by others. Later, the Millennium and Stellaris phaco machines (Bausch + Lomb, which had acquired Storz) also incorporated active pressurization as an option, but again it was rarely utilized, as it was somewhat more expensive and not actively promoted by the company. It was obvious to those of us who adopted active pressurization technology early that it generated superior anterior chamber stability and made surgery easier, safer and more efficient.
With the advent and increasing popularity of microincision cataract surgery in the new millennium, both biaxial and coaxial, delivery of adequate fluid into the anterior chamber became a significant challenge, and leading surgeons, led by the innovative Agarwal family, developed their own methods to pressurize the bottle through air pump infusion into the balanced salt solution bottle, again advancing the art and science and making surgery safer and more effective.
Now the market leader in phaco equipment sales worldwide, Alcon has launched its first machine with active pressurization. The Centurion utilizes a unique and highly responsive method, applying pressure to a plastic bottle of balanced salt solution, which generates a very responsive system. In my practice, I have access to the Bausch + Lomb Stellaris with active or “passive” (bottle height to set inflow) pressurization, the Abbott Medical Optics Signature with passive pressurization and the Alcon Infiniti with passive pressurization. While each of these machines is excellent and has attractive and unique features, I found myself drawn to the Stellaris primarily because of the active pressurization. Recently, I was given the opportunity to do about 40 cases with the new Centurion and found its active pressurization a significant advance over the gravity-controlled inflow of the Infiniti.
There are other phaco machine features that affect performance, including ultrasound power method, modulation and control, dual vs. single linear control of power and vacuum, peristaltic vs. venturi pumps, and the quality of adjunct features such as vitrector quality and cutting speed, to name a few. However, for me, the most dramatic advance is the increasing ability to access active pressurization, which I find generates a more stable chamber and makes surgery easier, safer and more efficient. I know of no vitreoretinal surgeon who would accept gravity-controlled passive pressurization when performing a complex vitrectomy with epiretinal membrane peel. I predict the same will soon be true for the cataract surgeon once he or she experiences the benefits of active pressurization.
I am confident that cataract surgeons who experience the benefit of active pressurization in their cataract surgery will find it a meaningful benefit. Once again, the magic of the “innovation cycle,” catalyzing constructive collaboration between innovative surgeons and talented engineers in industry, and fertilized by adequate capital, brings us new methods to provide enhanced care for our patients.
Disclosure: Lindstrom is a consultant for Abbott Medical Optics, Alcon and Bausch + Lomb.