The Dawning of Femto-Phaco
The Dawning of Femto-Phaco
What should you expect to change with laser cataract surgery?
When cell phones were invented in the 1970s, few could have predicted just how far the technology would develop. Back then, minutes were expensive and the clumsy-looking devices were considered a luxury that was installed in cars. Now of course, the pocket-sized gadgets serve as our lifelines, allowing us to do everything from check e-mail and get directions to play games and share photographs. Minutes cost mere pennies.
There are few topics in the current ophthalmic community that are as hotly discussed as femtosecond cataract surgery. As the game-changing technology emerges on the market, many practices are researching whether they're ready to take the financial plunge and commit to purchasing a machine. But is the laser worth it? Can an increase in patient safety or premium IOL success be documented? How will the system affect surgical flow and techniques? Top cataract surgeons provided their insights on how they think femtosecond lasers will improve outcomes and shared their top tips for fine-tuning the new techniques.
Refining Surgical Technique
William Culbertson, MD, of Bascom Palmer Eye Institute, an investigator for Optimedica's Catalys laser, says the biggest adjustment cataract surgeons will have to make with the new equipment is learning to properly dock the eye. Ideally, he says, the eye should be coupled with the center of the laser without any tilt to the eye or lens to avoid inducing folds in the back of the cornea that would compromise the laser beam's focus. “Just as if you're treating astigmatism with a limbal relaxing incision, you have to have the eye properly oriented with marks on the cornea that can be matched up with the registration mechanism on the laser so the beam goes where it needs to be.”
He places great importance on gaining familiarity with the laser's software. Each system offers a wide range of features, and it is crucial to understand how exactly the laser is working and what settings are best. For example, because the procedure pre-chops the nucleus, surgeons no longer have to make as many maneuvers inside the eye to divide the lens into quadrants or sextants. This leaves the best pattern for softening still to be decided, Dr. Culbertson explains. He says that using eccentric patterns and extra energy are unnecessary and may actually scatter the lens more, so leaving those settings turned off may be the best bet.
He also recommends being conservative with incision depth. “If there are still small areas of attachment with the capsule, you don't want to create a radial tear, even though it appears completely separated.” Residual tags need to be cut through at just the right angle, he says.
Michael Knorz, MD, of Mannheim, Germany, has implemented Alcon's LenSx as the standard for his cataract surgeries since a majority of his patients are receiving premium lenses. About 60% of his surgeries are refractive lens exchanges in presbyopic hyperopes that are around 50 to 60 years old. Because most of these patients' lenses are still soft, the femtosecond laser is capable of liquefying them. He does an entirely laser-based procedure on theses cases, using the laser and irrigation/aspiration only. For patients with denser cataracts, he uses the laser for a pre-chop to divide the nucleus into four quadrants before standard phacoemulsification.
Dr. Knorz is particularly enthusiastic about the femtosecond laser's capabilities regarding astigmatism correction, citing that phaco procedures do too little to address pre-existing astigmatism and effective lens position. Though the debut of toric IOLs has improved astigmatism, he insists that doing correction during the lens surgery is extremely valuable since the corneal plane is where the astigmatism actually occurs. Since the femtosecond system measures corneal thickness with real-time OCT exactly at the location of the planned incision, there is an increase in precision. Coupled with the reproducibility of incision length and arc shape, surgeons can look forward to consistent, predictable astigmatism correction.
Reorganizing the OR
What does a femtosecond laser mean for the workflow of your office? Incorporating a new piece of equipment into practice—particularly something as substantial as a new laser system—may require some changes to your surgical setup.
Dr. Culbertson recommends that if the laser is in a separate vicinity outside of the operating room, there should be ample space to use the laser and move the patient in and out. The area needs to be HIPAA-compliant, so the space must be identified and designed accordingly.
Because the high cost of the laser will require surgery centers to watch their finances carefully and maximize OR efficiency, he says that having the laser outside of the OR is likely the best plan of action for the majority of centers. Since it is only affordable to have one laser per site, surgeons can use the laser outside of the room and have the patient moved while they go into the OR and do another case. The setup should also be conducive to proper timing for the components of the surgery, allowing around 30 minutes between the laser and the initiation of cataract surgery. Waiting much longer, he warns, will allow the pupil to get too small.
“The timing needs to be right because when the laser opens the anterior capsule, some elements are released. The aqueous has access to the lens material and initiates some production of chemicals in the eye that could make the pupil constrict. You can't do the laser treatment two hours prior to surgery.”
He also points out that it can be impractical for femto lasers used in LASIK to be located where you do refractive surgery and then have to transport the cataract patient to where you will perform their procedure.
While Dr. Knorz agrees that most femtosecond setups will feature the laser outside of the OR, he has found it best to keep the system right in his laser suite, where he also has a surgical microscope and phaco machine. He finds this dynamic easiest on patients because of the minimal movement. With the patient on a pivoting bed, he irrigates the conjunctival sac with diluted betadine and drapes the eye and lashes before using the laser. Once suction is turned off, he lowers the bed and places the patient under the surgical microscope for standard phacoemulsification or irrigation/aspiration.
Rationalizing the Expense
The most controversial component of the femtosecond puzzle? No surprise: It's the cost. The machines themselves are a pricy investment for any practice, and when used as an add-on to premium IOL procedures, the surgeries become a big financial proposition for patients. Not exactly a welcome development when the economy is struggling to reboot.
A. James Khodabakhsh, MD, of Beverley Hills, raises the question that everyone is thinking: “Is this femto laser really necessary?” His response, when you learn that his practice is one of the first in southern California to purchase Alcon's LenSx laser, may surprise you.
“The answer is no. We are having amazing results doing cataract surgery manually. The complication rates are quite low and the outcomes are wonderful,” he says. But while it's true that masterfully trained surgeons produce great results day in and day out and have no need to rely on an automated system, what of the surgical community as a whole? This, Dr. Khodabakhsh argues, is where femtosecond cataract surgery deserves to be investigated on a deeper philosophical and practical level.
“In the real world, not all surgeons are the same. There are many with higher rates of complications and poor outcomes more often than not.” Research confirms that he's right. Dr. Knorz points to the recent MarketScope research that found that over 50% of cataract procedures performed in the US in 2010 did not address either the induction or correction of astigmatism. Any surgeon who routinely corrects complications from previous procedures can see the value in a system that would aid in getting things right the first time around. “This machine will truly benefit surgeons with the important steps of cataract surgery and, as a result, will benefit those patients who might have had serious complications otherwise,” says Dr. Khodabakhsh.
Is it worth it for patients and surgery centers to pay out of pocket for this technology, even before hard data about surgical outcomes has yet to materialize? If the ophthalmic community wants to progress toward a significantly raised standard for cataract surgery, Dr. Khodabakhsh says yes. “In my opinion, femto cataract surgery will be the only way the procedure is done in the next 15 to 20 years. We need to work out the kinks now for the future. Innovation cannot be stopped.”
A clear-corneal incision made with a femto laser is indicated at the red arrows. IMAGE COURTESY OF WILLIAM CULBERTSON, MD.
Answers Still to Come
While most ophthalmologists are near-unanimously enthusiastic about the positive impact femtosecond lasers will make on cataract surgery, concrete data on improved patient outcomes still has yet to surface.
Uday Devgan, MD, of Beverly Hills says that in the limited initial studies, there was only a small difference in endothelial cell loss and decreased levels of CME using the femtosecond laser in comparison to an experienced surgeon using traditional methods. As the chief of ophthalmology at UCLA's largest teaching hospital, his biggest concern resides in the future of teaching.
“Will new ophthalmologists still learn the manual techniques or will everything be automated? Most residents don't learn manual extracap cataract surgery, but I insist that every one of my residents still learn the old technique in addition to the new phaco techniques.”
Though the transition to fully automated cataract surgery will take years, there's no question that it is crucial for incoming ophthalmologists to stay well versed in both types of procedures. But if the currently progressing studies show significant increases in safety, as many predict, how long will it be until manual techniques become outdated?
Roger Steinert, MD, director of the Gavin Herbert Eye Institute at the University of California, Irvine says that evidence regarding procedural safety and long-term patient outcomes will come with time. “If intraocular surgical time, ultrasound energy and other manipulations are reduced with the laser techniques, complications like endothelial cell loss should indeed be reduced.” He predicts that the next step in research will be to prove better IOL power accuracy with the laser.
Any time a new technology appears on the market, there is a flux period in which devices and techniques are refined, which is important to consider when reviewing the first rounds of data that will surface in the coming years. Dr. Steinert anticipates that there will be a rapid evolution of the laser systems themselves, as well as the development of many new surgical techniques and supporting instrumentation.
“The next few years should be very dynamic,” he says. OM
Ophthamology Management, Issue: August 2011