May 2014

 

CATARACT

 

Conquering the curve


by Keith A. Walter, MD

 
 

Keith A. Walter, MD

 

A femtosecond laser for cataract surgery performs four moderately difficult steps with exactness and speed, significantly reducing the possibility of human error: incision of the eye, capsulotomy, hydrodissection, and lens fragmentation. If you are hesitant to incorporate lasers into your surgical toolbox for cataract patients due to apprehension over possible downtime or navigating a steep learning curve, now is the time to reevaluate those concerns. Designed and engineered with the needs of the surgeon and patient forefront, the latest generation of laser cataract surgery machines is user friendly, precise, and fast.

Selecting a laser

There are a number of different femtosecond lasers now approved for cataract surgery, and owning one with the right platform to suit the needs of your practice enhances the skills of the surgeon as well as provides security for your patients, safety during the procedure, and ultimately, better outcomes. Ease of use and high-quality imaging are important considerations for us.

The laser we chose eliminates the need for a lid speculum by using a two-step docking procedure with a liquid interface. Docking in two steps provides more control for the surgeon, thus greatly reducing the possibility of lens tilt caused by patient movement. Time-wise, I find that the additional step is inconsequential. In addition, dispensing with the lid speculum increases patient comfort, as well as eliminates distortion. The resulting liquid optics allow very high resolution optical coherence tomography (OCT) imaging that provides clear visibility of structures within the eye while avoiding any corneal distortion of induced folds. The OCT image allows the surgeon to create a complete capsulotomy with exact placement1 and achieve a precise incision, increasing the likelihood of self-sealing and reducing the possibility of infection.

Effortless training

A well-designed quality interface simplifies the learning process, such as provided by the new touch screen interfaces. Following a review of training materials provided by the manufacturer, an experienced trainer provided a 2-hour training session. This included a step-by-step simulation of an actual procedure. After just a few hours of prep work and training, I was ready for the first day of surgeries. I selected 6 patients with relatively uncomplicated cases for my initial laser procedures. As an experienced LASIK surgeon, I am already acquainted with the process of placing the suction ring around the eye and acquiring centration around the cornea, so I found that process quite easy. However, working in a teaching hospital environment, I have seen even surgeons who do not have previous LASIK experience learn the procedure in just one training session. Not only was the initial learning curve very reasonable, in less than 2 months, I have taken my procedural time from 5 to 6 minutes down to 3 or 4. The ease of use and safety afforded me by using the laser machine contributes to great outcomes, allowing me to offer a better product to my patients.

Integration

Integrating a laser cataract machine into my practice was a seamless processpatients want this technology. They find comfort and reassurance in knowing that their surgeon is using the best technology available. To help my patients understand their options and to build their confidence, my office implemented a basic patient education program outlining the patient's options with respect to laser or traditional surgery and intraoperative lens selection. We provide our patients with an educational video of the procedure and then inform them of the additional costs associated with laser surgery and selection of a premium lens. We find that patients are not hesitant to pay more for the laser surgery.

Standard case

In the accompanying video, I demonstrate the standard operating procedure using a Catalys Femtosecond Laser and Whitestar Signature phacoemulsification system (Abbott Medical Optics, Santa Ana, Calif.) on a typical patient who presents without complications.

To begin, we dock the patient under the laser by placing a suction ring around the eye. Once gentle suction is achieved, balanced salt solution is poured in the cone. The liquid interfaces with the laser machine to provide high-quality imaging on the OCT screen. The patient does not experience any pain or discomfort during this portion due to topical drops and mild IV sedation administered previously. We then dock the liquid-filled cone with the laser.

The integral guidance processing system takes 10,000 images of the eye and projects the lens, cornea, and pupil in both axial and sagittal views on the screen. The laser fires and makes the initial capsulotomy incision in the eye in less than 1.5 seconds, forming tiny "champagne bubbles" due to the creation of gas. During the next minute and a half, the laser breaks apart the lens into a grid pattern, starting from the deepest part of the lens and moving forward. The final step on the laser is the incision into the anterior chamber through the cornea. The patient is then undocked and brought to the operating room for the remainder of the cataract procedure. Draped for surgery and under light anesthesia, I then insert a lid speculum to hold the eye open. Looking through a surgical microscope, I use a diamond blade to make a small sideport incision and inject viscoelastic to inflate the anterior chamber. I then open the main incision with a pair of forceps and lift off the circular capsulotomy, opening access to the cataract. Hydrodissection is still needed to separate the cortical fibers from the capsule, but hydrodelineation is no longer necessary when using the femtosecond laser as the gas formed accumulates around the nucleus, making the lens freely mobile. Having the lens always spin freely in the capsular bag has been a pleasant surprise in using the laser, and I think an added benefit. After cortical evacuation over the center of the lens, I only need to emulsify a small amount on the surface of the lens before it is ready to be split into two pieces. With mild pressure, the cataract cracks and separates completely and easily. Next I rotate the lens and find the laser incision sectioning off each quadrant and use mild pressure to crack along the "fault line." After I section off the quadrants, I use the peristaltic setting on the Signature to grab a quadrant out of the capsular bag. Once this initial quadrant is acquired over the pupil, I switch to Venturi vacuum, which allows for quick annihilation of the fragments while maintaining excellent chamber stability. The pieces evenly flow into the phaco tip without much manipulation because of the previous fragmentation into the grid pattern by the laser. I do the same for all remaining quadrants. Once the nucleus is removed, I use a polymer tip I/A device to remove the cortical layer, leaving only the capsular bag with the perfectly round capsulotomy.

Conclusion

The addition of the laser cataract machine to my practice has been a progressive change. It is easy to learn how to operate, so I was able to begin patient surgeries immediately after installation. Consistent and positive outcomes contributed to the integration of the machine and conversion of patients for two reasons: First, our patients already want the technology. Second, the ease of use and safety of the machine have created a level of enthusiasm with me and among the staff, which we pass along to the patients.

Reference

1. Abell RG, Kerr NM, Vote BJ. Femtosecond laser-assisted cataract surgery compared with conventional cataract surgery. Clin Experiment Ophthalmol 2013 Jul; 41(5):455-62.

Editors' note: Dr. Walter is a professor of surgical sciences at Wake Forest University Eye Center. He has financial interests with Abbott Medical Optics.

Contact information

Walter: kwalter@wakehealth.edu

Conquering the curve Conquering the curve
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