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Large series shows increased safety, efficiency, efficacy with laser-assisted cataract surgery
A proprietary femtosecond laser system (Catalys Precision Laser System, OptiMedica) is being used to perform cataract surgery in all comers.
By Cheryl Guttman Krader; Reviewed by Burkhard Dick, MD
Bochum, Germany-A femtosecond laser system is improving cataract surgery safety and enabling treatment of challenging cases with broad inclusion criteria.
A review of experience with the first 850 cases of laser-assisted cataract surgery using a proprietary femtosecond laser system (Catalys Precision Laser System, OptiMedica) shows there are advantages for using the technology in routine and challenging cases.
Key features of the image-guided device were described by Burkhard Dick, MD, professor of ophthalmology and chairman, Ruhr-University of Bochum, Bochum, Germany. He presented data demonstrating the system’s reliable performance and capabilities for delivering superior outcomes compared with procedures done with conventional cataract surgery techniques.
“[The platform] allows a gentle dock, creates perfect corneal cuts, provides better vision than conventional surgery, and is bringing us close to eliminating the need for ultrasound,” he said.
Dr. Dick noted that the femtosecond laser has a liquid optics interface. IOP increases only 10 mm Hg after application of the suction ring. Docking is possible for all comers, including Asian and pediatric patients and as well as patients with strabismus, plus those with previous glaucoma filtering surgery.
Complete capsulotomy was achieved in more than 99% of the 850 eyes in his series and in 93% of 27 eyes with mature, white cataracts, he noted. Results from a prospective, randomized, fellow eye-controlled, single-surgeon study showed that eyes having femtosecond laser-created capsulotomies had significantly less capsular bag shrinkage compared with eyes operated on with conventional techniques.
Use of the femtosecond laser for lens fragmentation resulted in significant reductions in ultrasound requirements, measured as effective phacoemulsification time (EPT) on a proprietary phacoemulsification platform (Stellaris, Bausch + Lomb), across all Lens Opacities Classification System (LOCS) III subgroups of eyes.
“For the femtosecond laser group, median EPT was 0 in grade 2 eyes, close to 0 in grade 3 eyes, and 0.19 seconds in grade 4 eyes,” Dr. Dick said. “Compared with groups of eyes having conventional surgery, these values represent reductions in ultrasound usage of 100%, 98%, and 95%, respectively.”
In a series of 57 eyes with grade 5 very dense cataracts, mean EPT was 2.24 seconds and <1 second in almost half of the eyes.
“Ultrasound energy is still needed to remove these brunescent to rubra lenses, but the amount of energy used is comparable to that associated with my conventional surgery for grade 3 cataracts,” Dr. Dick said. “So, it is a great technical advantage to pre-treat the grade 5 lenses with the femtosecond laser.”
Using a 350-µm grid pattern for the fragmentation, 40% of the first 850 cases (mean LOCS III = 3.2) were completed with no ultrasound, he noted.
“After changing my phaco tip, software settings, and instrumentation, and adopting a mental change about the need for phaco, 87 of my last 100 cases were done without ultrasound energy,” Dr. Dick said.
Results from a prospective intraindividual comparison study showed eyes treated with the femtosecond laser had 19% less inflammation on postoperative day 1 relative to conventional controls, as well as superior best-corrected visual acuity outcomes at 6 hours and 3 and 7 days postoperatively.
The precision achieved using the femtosecond laser to create corneal incisions was demonstrated in an eye that was treated prior to undergoing enucleation for a malignant ocular tumor.
“The laser was programmed to create a 30º angular cut, keep the epithelium intact, and cut through Bowman’s membrane to 200 µm above the endothelium,” Dr. Dick said. “We were impressed with its performance in achieving all of these criteria.”
Dr. Dick noted that he is continuing to discover new applications for the femtosecond laser in cataract surgery, including posterior capsulotomy, the bag-in-the-lens technique, and capsulotomy in pediatric eyes.
Burkhard Dick, MD
Dr. Dick is a consultant to Abbott Medical Optics, AcuFocus, Allergan, AqueSys, Bausch + Lomb, Bayer, Calhoun Vision, Carl Zeiss Meditec, Domilens, Geuder, Hoya, Morcher, Novartis, Oculus, Ophtec, Optical Express, OptiMedica, PowerVision, Pfizer, and Transcend Medical. This article is adapted from Dr. Dick’s presentation at the 2012 annual meeting of the American Academy of Ophthalmology.