Few would argue with the importance of phacoemulsification to our profession and to our patients� vision. But many have argued that we�ve now reached the technological limits of this technique.
Our research group is challenging this notion with a new technology that should let eye surgeons dramatically reduce their cataract surgery time and complication rate. Imagine an anterior capsulotomy not dependent upon a red reflex, that takes 2 to 3 seconds to perform, that can be revised in seconds and that allows easy repair of radial tears in the capsule. All this is possible with the use of plasma technology.
An advance such as this is critically important now, both for reasons of patient safety and because of the economic issue we all face � the viability of a profitable cataract reimbursement for both surgeon and hospital.
New horizons
Several groups today are working on ingenious systems aimed at replacing phacoemulsification. Our work, however, is intended to catapult phacoemulsification to a much higher level of efficiency.
To accomplish this, our research team is exploring a novel approach to surgery employing a new instrument we call the Plasma Blade. This instrument uses new technology involving the fourth state of matter (beyond solid, liquid and gas), known as plasma. Plasma technology gives us a new way to create an incision into solid or semi-solid matter.
The Plasma Blade is a handheld device with a filament about the width of a human hair that can be shaped in a number of different ways. An electronic charge pump causes the upper layer of atoms in the filament � about a micron deep � to transform from the solid state into the plasma state. A focused electromagnetic field is used to control, contour and shape these plasma particles into a plasma cloud around the filament.
The atomic particles that make up this plasma cloud are in such a high state of agitation that they literally dissolve the molecular bonds of the material they come in contact with, creating an incision 20 to 40 times sharper than an incision made with a diamond blade. And the tiny filament doesn�t bend, even when cutting through something as strong as cowhide, because it never touches the material. The plasma cloud dissociates the material faster than the hand can move the instrument.
Again, the filament itself doesn�t cut anything; the plasma cloud creates the incision. In fact, an uncharged plasma blade filament has no real cutting ability. It has difficulty even abrading corneal tissue.
The Smart Blade
An obvious concern with this technology is that something that cuts so easily could be difficult to control. In fact, we�ve developed a proprietary tissue-sensing system that uses an electronic echo to identify the material or type of tissue within a given distance of the filament. When this feature is in use, we call the instrument the Smart Blade, because it can be programmed to recognize the tissue you don�t want it to incise. When the blade senses proximity to that tissue, the instrument is instantly gated off, eliminating the plasma cloud and transforming the filament back into a harmless microelectrode.
This capability opens an enormous field of possible uses for the instrument. For example, radial sclerotomy incisions can be made to within 50 em of the choroid, with the blade gating off when the filament comes closer than that distance. This may make it possible to perform presbyopia reversal surgery.
Plasma vs. electrosurgery
Doctors often ask about the difference between plasma technology and classic electrosurgery. The difference lies in the way the incision is made. Classic electrosurgery directly employs an electrical current from the instrument to break apart the material in question. In contrast, the Plasma Blade uses electric power indirectly, as a means to create the plasma cloud, which then creates the incision.
The difference in efficiency is remarkable. Diathermy units require more than 100 watts to create an incision. The Plasma Blade requires 10 watts, and the resulting incision is cleaner. And in contrast to a more time-consuming capsulotomy performed using a classic electrosurgical tool, a plasma blade capsulotomy requires an average of 2 to 3 seconds to perform. Also, the Plasma Blade is remarkably compact; it achieves a new level of miniaturization of ophthalmic instrumentation.
Safer capsulorhexis
Our goal in creating an instrument using plasma technology is to replace what many consider the most unpredictable and potentially dangerous part of modern cataract surgery: the anterior capsulorhexis.
Most surgeons will admit that it�s not uncommon to lose control of the capsulorhexis temporarily (or even permanently) during the procedure. And as you know, different types of cataracts can pose their own special difficulties. At the same time, a perfect capsulotomy opening greatly decreases both the difficulty of phacoemulsification and the risk of operative complications.
Harnessing plasma energy with a tool such as the Plasma Blade makes it far easier for you to perform a capsulotomy. You simply trace over the anterior capsule, and where you trace will be the precise location of the capsulotomy. If you�re dissatisfied with the original capsulotomy size, you can simply trace around part or all of the entire original capsulotomy opening to enlarge or reshape it.
Even if you tear the capsular rim during phacoemulsification, reinserting the Plasma Blade will let you trace around the radial tear, leaving a smooth edge and eliminating the capsule segment containing the tear.
A step in the right direction
This kind of speed, accuracy and versatility when performing capsulotomy should help to raise phacoemulsification to a new level. For example, Plasma Blade capsulotomy will provide the more precise capsulotomy size needed to perform Dr. David Brown�s "phaco flip."
Of course, Plasma Blade capsulotomy won�t replace the need for highly skilled ophthalmic surgeons. But it will eliminate unnecessary surgical time and unnecessary risk during surgery, much as other modern approaches to cataract surgery have done.
By taking the drama out of anterior capsulotomy, we in effect streamline modern cataract surgery. And although no system is perfect, the combination of Plasma Blade capsulotomy and modern phacoemulsification technology will surely let vast numbers of eye surgeons dramatically reduce their cataract surgery time and complication rate. This, in turn, should cause surgeons with technological skill to be welcomed by hospital administrators who now more than ever make "bottom line" decisions. Hopefully, this will help salvage cataract surgery for most ophthalmic practices.
Realizing potential
Dr. Charles D. Kelman � creator of phacoemulsification � was a true pioneer in ophthalmology, perhaps the greatest of our time. "Through My Eyes," his autobiography, chronicles the monumental hurdles he had to overcome, as both a researcher and a clinician, to put phacoemulsification into the hands of the clinical ophthalmologist.
This book is a powerful reminder of the challenges that are often involved in making a technological breakthrough � the extraordinary creativity required and the human story behind the technology. And it makes it clear that the struggle for technological breakthrough is not much different today than it was during the 1960s.
For that reason, we realize the road to acceptance of such an unusual new technology may not be a smooth one. A prominent ophthalmologist has said that the Plasma Blade concept is exciting but that it will take a heroic effort to place such technology in the hands of clinical ophthalmologists. Truer words could not have been spoken.
At this point, Plasma Blade technology has been submitted for FDA review. Next will come the challenges of gaining FDA approval and bringing the blade to market.
As Dr. Kelman�s autobiography shows, extraordinary feats often require extraordinary efforts. Nevertheless, we hope to see this new technology live up to its full potential, helping to make phacoemulsification a more efficient and safer procedure, and in the process, helping to maintain the status of cataract surgery as a viable procedure for most ophthalmic practices.
Dr. Richard Fugo: The Man Behind the Blade
Dr. Richard Fugo, inventor of the Plasma Blade, is a self-described "low-key guy;" a clinician who prefers sitting in his lab solving a problem to lecturing or making public appearances. When asked about his life, he insists there isn�t that much to say. But his modesty belies an interesting story.
Although he earned a Ph.D. in human physiology and neurophysiology before attending medical school, his interests have always included a broad range of the physical sciences. While earning his master�s degree at Villanova University, he worked closely with a professor interested in bio-electronics; later, his Ph.D. advisors emphasized strength in math, statistics, chemistry and physics. Eventually, physics became something of a hobby for Dr. Fugo. Along with numerous courses he�s taken over the years, his personal library contains nearly 40 volumes on the subject.
Being an inventor requires a certain kind of mindset � independent, analytical and creative. Dr. Fugo credits his medical school experience with pushing him in that direction.
He studied at the University of Bologna in Italy. "The university system in Europe is much more fluid than the one in the States," he explains. "You enroll, they tell you what you need to accomplish, and then you decide how to accomplish it. There�s only one exam for each course � an oral exam before three professors � which is given only when you request it. That means you can take years to prepare, if you feel you need it. You�re required to take a great deal of personal initiative in the education process � sort of like earning a Ph.D. over here."
Dr. Fugo found this environment stimulating, and acknowledges that it encouraged him to become even more self-motivated and to look beyond answers provided by other people.
After completing his internship and residence, Dr. Fugo went into practice as an ophthalmologist. But as a new doctor just starting out, he found that he had time on his hands.
"Rather than sit around, I thought it would be educational to dissect different kinds of eyes, such as a cow�s eye or pig�s eye. What I discovered, almost immediately, was that the tools available for cutting weren�t very good, especially when it came to cutting through tougher tissues like the sclera."
Finding an effective means of cutting through dense tissue became a puzzle, and he was determined to solve it.
"I tried many kinds of blades � diamond, sapphire, stainless steel, chemical and electrical. My research lab had a lot of advanced electronic equipment, and because of my interest in physics I kept returning to electronic possibilities. But the efficiency of the existing electronic knives was poor. They essentially use the tissue as an electrical resistor, generating heat and burning through tissue. I knew there had to be another way."
Eventually, Dr. Fugo�s persistence led to the development of the Plasma Blade. He�s reluctant to take sole credit for the invention; he points out that he�s worked with many people to develop the blade over the past few years. Nevertheless, it seems clear that he really is the driving force behind the invention, and his pride and excitement about the future possibilities of the instrument are obvious.
As a closing thought, he mentions that he likes to spend his weekends building things around the house, sometimes working with friends who are skilled carpenters or stonemasons. He says he�s learned a tremendous amount working with them.
"Learning from people who have expertise in areas outside of your own is a wonderful experience," he explains. "We�re all students throughout our lives. The secret is just finding the right people to teach us."
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