Amid a considerable level of excitement, presenters at this week's meeting of the European Society of Cataract and Refractive Surgeons discussed everything from the latest safety and efficacy data to cost-benefit analyses and what exactly this exciting new technology should be called.
Why the excitement?
Zoltan Nagy, MD, a leading pioneer in the field, has been performing femtosecond-assisted cataract surgery for three years. He says to date about 2,000 procedures have been done worldwide.
Nagy calls it "laser-created, surgeon-controlled surgery" that results in perfect capsulotomies in size, shape and centration. Richard Lindstrom, MD, said he was surprised to find the laser-created capsulotomies were also stronger, not weaker.
Nagy's data shows that compared to phacoemulsification, laser surgery uses 51 percent less phaco power and 43 percent less phaco time. As a result, patients experience less edema and faster visual recovery, fewer HOAs and better quality of vision. He believes that it might also reduce the risk for cystoid macular edema and result in less endothelial cell loss.
But will the perfect capsulotomy result in the perfect surgery? Roger Steinert, MD, asked. "I do think the capsulorhexis is the biggest source of variability that we don't have control over. I'm not sure making the perfect capsulotomy will lead to the perfect outcome. That's far too simple." He urged ophthalmologists to record their data to validate that the creation of a perfect capsulotomy is indeed a big step forward.
Currently available technology
The femtosecond laser devices for cataract surgery are more complex than the ones for flap creation. They require very precise imaging systems and a docking system that does not cause significant IOP rise and preserves the anatomy of the cornea and intraocular structures. If you currently have a femtosecond laser system for refractive surgery, you will need another laser for performing cataract surgery. You will also continue to require a phaco machine at this time. No femtosecond laser on the market can remove the lens particles.
William Culbertson, MD, said that the four available systems were developed to make the primary clear corneal incision, paracentesis, capsulotomy, lens fragmentation and limbal relaxing incisions. But they differ in two areas: the docking system and how they image the eye.
The LenSx and Victus systems (the new venture announced last week between Technolas and Bausch & Lomb) use a curved, contact lens interface, while the Optimedica's Catalys and LensAR systems use a liquid optics interface in which a no-touch, non-applanating suction fixation device (liquid is automatically filled inside the suction ring) provides an immersion ultrasound interface similar to ultrasound biometry.
Culbertson said the liquid interface causes less IOP rise, less subconjunctival hemorrhage, less eye drift and most importantly better image of the lens and capsule and better optical analysis of corneal folds.
Doug Koch, MD, presented data showing that there was little to no IOP rise with the liquid interface and it produced 40 percent reduction in subconjunctival hemorrhage.
Ron Krueger, MD, described LensAR laser system's unique imaging system which uses high-resolution 3D confocal structured illumination (CSI), a form of infrared-based imaging. The resulting 3D reconstruction allows for a more complete image the lens and accounts for lens tilt.
More precise limbal relaxing incisions
Eric Donnenfeld, MD, noted that only about 25 percent of surgeons perform LRIs to correct astigmatism during cataract surgery because they are imprecise. But he predicts that's about to change.
"This technology has taken LRIs from an art form and moved it to a science," Dr. Donnenfeld said. He says the accuracy of the laser and the ability to make late adjustments during the procedure or after surgery at the slit lamp allows for a more repeatable surgery.
His study of 14 patients showed that 86 percent were left with .5 D or less of cylinder and 71 percent were within .25 D.
Who's a good candidate?
The system can be used on + 1 through +4 lenses; however, it's not appropriate in small pupils, cloudy corneas or very mature lenses. Financial constraints aside, Nagy said he would use it in 80 to 90 percent of his patients, while Culbertson put the figure at 98 percent
Gerd Auffarth, MD, reported using the laser on black cataracts, as well as a patient with pseudoexfoliation and to implant a toric IOL in a patient with one amblyopic eye. All had good visual outcomes and experienced no complications.
Steven Slade, MD, said the learning curve is short, but you will have to modify your technique.
"The first instrument in the eye is the phaco tip, which is used to vacuum up the capsule. There's no need to hydrodissect or pre-chop. It will change your technique and will enable you to do things you've never done before."
He said they have not observed any complications that are not seen with phaco. They have observed no problems with docking time and no sign of damage to the retina. Patients do experience conjunctival redness, similar to LASIK.
Nagy said he has never experienced complications, but if you're not careful you can break a capsule or get zonular weakening. "With proper patient selection and being mindful of safety limits, you can avoid complications 100 percent," he said.
Dr. Slade he knows of two cases of dropped nuclei, which were likely the result of a particularly aggressive hydrodissection technique and not the fault of the laser.
What do we call it?
Capitalizing on the public's awareness of LASIK, Drs. Krueger and Lindstrom are advocating Laser Refractive Cataract Surgery or LARCS.
"I don't know if it will stick, but it best defines what's going on," Dr. Krueger said.
Dr. Nagy suggests FLRCS Femtosecond Laser-assisted Refractive Cataract Surgery. Because Medicare won't pay for laser cataract surgery but does allow an extra charge for refractive surgery, Dr. Culbertson called for Femtosecond Laser Treatment Prior to Cataract Surgery.
The short answer is that it's too soon to tell, said Paul Rosen, MD. "There is great variability between countries and regions, private and public practice. Is it cost-effective? Admittedly, my presentation is about a year too early. It's too early to say because the costs are not well-defined."
However, he provided a theoretical cost-benefit analysis. Well-respected practice consultants figure about 30 percent of patients would be willing to pay an additional $1,000 for femtosecond cataract surgery.
The laser costs about €400,000, amortized over a five-year period. Consider €45,000 a month for maintenance and €400 euro per click fee. If you did 25 eyes a month, you would need to charge €900 euro extra to breakeven. If you did 64 eyes a month, you would need to charge €600 euro.
Rosen noted that when phaco was introduced in 1989 most said it was too expensive and a good surgeon could achieve the same results. But in the eight years that it took to conduct a randomized controlled trial to compare it to ECCE and the benefits were clear, the technique was accepted.
"I predict the same will happen with the femtosecond laser," Rosen said. "It will be gradually introduced into the public sector over the next five to 10 years. It's a powerful technology that's here to stay."