A system born out of need, demand

Femtosecond laser cataract surgery suites help guide surgeons to accurate results.

By Zack Tertel, Senior Editor

Before the birth of the femto-cataract surgery suite, Denise Visco, MD, took paper and pen to create a surgical planning worksheet. It was insurance, she says, against potential error and helped to guide the surgery to ensure an optimal patient outcome.

Those days are long gone: The modern cataract surgery suite arose out of surgical necessity and patient and physician demand. Early femtosecond cataract-surgical procedures required much guesswork on the surgeon’s part, leaving open the chance for imprecise results. “There is an art and a science to implanting advanced technology IOLs (AT-IOLs), and surgeons are continuously seeking new ways to address the needs of cataract patients who live with astigmatism and presbyopia that could benefit from AT-IOLs,” says Patrick Sadd, global franchise director at Alcon.

Dr. Visco, surgeon at Eyes of York (Pa.), uses the LENSAR laser system, which she purchased in November 2012 to perform capsulotomy and lens fragmentation — the FDA had yet to approve it for corneal incisions. Now, the laser is part of a complete suite, it’s like a completely new system: She appreciates the system’s automation. No one needs to transcribe and transfer data from one instrument to another anymore, making surgery that much easier.

Many companies now manufacture the equipment and technology that has become increasingly necessary to provide accurate preoperative measurements, show measurements, guide during surgery and provide feedback on outcomes after surgery, says Kendall Donaldson, MD, MS, associate professor and medical director, Bascom Palmer Eye Institute in Plantation, Fla.

Patient satisfaction is always crucial, but it’s particularly true with femtosecond laser cataract surgery. A major shift started around 2003, says Dr. Donaldson, when presbyopia-correcting lenses became more popular in the marketplace. Patients were willing to pay out of pocket for these lenses, then femtosecond lasers became available to complement the premium lens technology. While patients in the 1970s may have been satisfied with wearing half-inch thick glasses, she says, patients today now expect to have near-perfect visioin sans spectacles.

The technology had to keep up to achieve better refractive outcomes and meet expectations. For example, Mr. Sadd says that Alcon is focused on is providing a portfolio of equipment that helps build surgeon’s confidence and consistency. “[Surgeons] are able to more confidently recommend an IOL that fits a patient’s lifestyle more than just the standard monofocal IOL and may also make them spectacle free.”

Here, industry experts describe how the technology helps to meet these expectations while improving the surgical experience for patients and surgeons.

Surgical planning

The preoperative diagnostic stage starts the surgery process. “Planning and executing cataract surgery requires considering multiple variables specific to each patient’s eye”, says Mr. Sadd. For instance, technologies like Alcon’s Verion Image Guided system capture high-resolution reference images of the eye and measure keratometry, pupillometry and other parameters all together. Also, many systems feature digital marker functionality to help incision placement and IOL alignment. For instance, LENSAR’s Streamline captures an infrared iris and pupil image. The data collected, such as the axis and magnitude of cylinder, wirelessly populates to the laser.

“Because all that info is saved electronically, our staff no longer has to transpose that data, so it eliminates errors,” says Lawrence Woodard, MD, of Omni Eye Services in Atlanta.

Many systems can also identify the conjunctival vessels and iris architecture, Dr. Woodard says. This is significant because cyclorotation occurs when patients lie down for surgery. Cyclorotation can cause errors when surgeons implant toric IOLs and treat astigmatism with incisions. Verion eliminates the need for preoperative and surgical markings, Dr. Woodard says.

“Using landmarks from the patient’s iris and sclera, Verion accounts for cyclorotation, which helps surgeons place incisions on the proper axis and with improved accuracy, which equates to a better outcome,” adds Mr. Sadd.

According to Dr. Visco, this is a big step forward. In prior years, after she had picked the axis and decided how much astigmatism to treat, she would use her paper nomogram to decide what to treat and then write out the parameters. “I actually drew a little picture of where the astigmatism incision should show up in case my technician put the data in wrong. When the picture would come up on the screen I could see where the incisions were and if they didn’t match my picture — that was a little ‘safety stop.’”

In the OR

At the suite’s center is the femtosecond laser, which takes information from other suite components to perfect the treatment. For example, the Zeiss Cataract suite preoperatively captures a reference image that, during surgery, is superimposed on the microscope to show the patient’s limbal blood vessels. The surgeon also can see the astigmatism axis to aid in navigation.

Similarly, surgeons can use the data captured on Verion intraoperatively, Mr. Sadd says. “Imagine this as making a map of the patient’s eye and using it as a guidance tool. So you have a digital overlay on the LenSx laser screen and in the microscope ocular itself, which helps guide surgeons placement of incisions, rhexis and IOL implantation all mapped to the patients eye.” Also, some cataract suites allow for customized laser energy based on the cataract. LENSAR’s laser uses only the amount of laser energy that is needed based on its cataract density imaging.

“In addition to determining density, our imaging system identifies the tissue specific anatomy such as the cataract nucleus, epinucleus and endonucleus,” says Nick Curtis, LENSAR CEO. “Based on the category the platform assigns to the cataract, there are automatic fragmentation patterns preset, so as soon as the surgeon identifies and matches that category the system has all the treatments preprogrammed to optimize laser energy use.”

Additional automation and customization options for many cataract surgery suites include fragmentation patterns based on lens density. The LENSAR laser uses pre-programmed patterns that correlate to particular lens densities. This minimizes the total treatment required, says Mr. Curtis, because the surgeon can treat a soft cataract differently than a hard cataract with dense nuclear material. Using less energy shortens a patient’s recovery as well, and the patients’ eyes appear clearer after surgery. “If you deliver phacoemulsification energy at a high magnitude, and longer time, then your corneas tend to be more cloudy the next day or you may see some cell flair,” adds Mr. Curtis. “The surgeon wants to see pristine eyes the next day.”

Postop

Some cataract surgery suites continue to help the surgeon’s accuracy long after the surgery. For instance, Dr. Visco says she uses the Streamline postsurgery to look at her results. If she finds that she is making too much or too little of a correction, she adjusts her nomogram. These systems create a surgical plan that gets optimal results as the surgeon continues to use it, says Dr. Donaldson, who uses Verion to input postoperative data. “For example, the plan will illustrate how the laser will create the limbal relaxing incisions, so your nomogram becomes more robust, and astigmatism correction improves as you enter more postoperative results into the system.”

Benefits

On their own, femtosecond lasers can create precise incisions, says Mr. Curtis. “But, at the end of the day, if the laser is not guided by biometric data and it still requires a manual inputting or use of various markers with which to treat, you’re still creating the potential for error.”

So, many of a suite’s benefits were designed to increase accuracy. Dr. Woodard says Verion and LenSx allow him to more accurately identify the steep axis to appropriately place the IOL. The result: He repositions patients’ toric IOLs less frequently. He’s also noticed more consistent placement of multifocal IOLs since using Verion.

The suite also makes him more efficient during the surgical procedure because he takes fewer trips to the preoperative marking area. “I’m decreasing the time that the patient is in the facility and decreasing the amount time I have to run back and forth.”

Increased precision and efficiency make for a confident surgeon. Dr. Visco says she experiences less tension during cataract surgery thanks to her suite. “I am much more at ease because I know it took the measurement right off the patient, I verified it, it went over on the computer and the laser is doing everything. There is no human error.”

In some cases, accuracy and efficiency go hand in hand. Mr. Curtis says that taking less time in procedures keeps the patient from having to lie still for too long. This means less chance of the patient moving during surgery; movement can lead to complications. Patients tend to stress prior to surgery, Dr. Visco adds, and so avoids much of the marking prior to surgery puts them more at ease and increases patient confidence.

Conclusion

Dr. Visco says femtosecond lasers have come a long way the last four years, thanks in large part to the surgery suites. “They’ve all had tremendous upgrades and improvements in efficiency.”

Still, manufacturers continue working to improve outcomes for both surgeon and patient. For example, Mr. Sadd says that Alcon has recorded more than 400,000 cataract surgery cases and 180,000 post-case outcomes in its database. “Using this data will allow Alcon to optimize surgeon factors so that the surgeon’s next case is better than the one before, and so on.

Also, surgeons’ continual input should lead to even better results and increased applications. Mr. Curtis says LENSAR listens to the surgeons about what will increase efficiency and accuracy. “It’s all about taking care of the patient in the most efficient fashion while improving outcomes.” OM