Cataract Surgery Moving Forward With Femtosecond Lasers

Caroline Helwick

November 19, 2012

CHICAGO — Femtosecond laser systems may improve outcomes for cataract surgery over conventional approaches, according to investigators who reported on large series of patients at the American Academy of Ophthalmology (AAO) and Asia-Pacific Academy of Ophthalmology 2012 Joint Meeting.

Femtosecond lasers have been on the market for about a year. The LenSx (Alcon, Inc) system was approved in 2011 and the Catalys (OptiMedica Corp) in September 2012.

"Laser cataract surgery is safer than the best published manual surgery data," said Michael Lawless, MD, from the University of Sydney in Australia, who presented a retrospective consecutive case-comparison review of his first 500 procedures done with the LenSx system.

The femtosecond laser system is associated with lower rates of complications compared with conventional phacoemulsification in published series, according to Dr. Lawless. This included a rate of 0.2% for anterior radial tears versus 0.79% to 5.6% in manual surgery controls, a complete absence of posterior capsule tears versus 0.45% to 2.09% with manual surgery, and zero posterior lens dislocation versus 0% to 0.12% with manual surgery.

Rates were also very low for parameters that lacked a comparison with manual surgery, including suction breaks (1%), manual corneal incisions (0.8%), pupillary constriction (1.2%), and anterior capsule tags (1%).

For the subgroup of patients who underwent both visual and refractive surgery (n = 141 with laser; n = 57 with manual surgery), there were no significant differences in numerous visual and refractive outcomes 3 months after the procedures.

"We saw no differences in outcomes on any metric we could measure," Dr. Lawless said. "Mean absolute error was better with laser than with manual surgery but this was not statistically significant."

In a second study, Burkhard Dick, MD, from the University Eye Hospital Bochum in Germany, reported on his group's experience with 850 cases using the Catalys femtosecond laser. Patients had a variety of difficult conditions, including intraoperative floppy iris syndrome, glaucoma, cornea guttata, small pupil, advanced/mature cataracts, pediatric cataracts, and others.

"These challenging cases were successfully treated with laser cataract surgery," Dr. Dick said.

Compared with manual surgery, laser surgery offered a more precise capsulotomy size and shape, as well as less capsular bag shrinkage (9.9 mm versus 9.6 mm by week 8; P < .005), he noted.

"There was over 99% complete continuous curvilinear capsulorhexis on all comers, including perfect diameter, position, shape and centration," he said. The device yields "perfect corneal cuts," he added.

In a series of 27 mature cataracts, capsulotomy was complete in 93%, and complications were limited to 2 extensions.

Fragmentation reduced the average effective phaco time in all grades of cataracts: by 100% for grade 2 cataracts, 98% for grade 3, and 95% for grade 4.

"Importantly," he added, "40% of the first 850 cases required no ultrasound… and for the most recent 100 cases, 87% required no phaco."

Femtosecond laser surgery was associated with a 19% reduction in postoperative inflammation by day 1 and with improved best-corrected visual acuity up to day 7. However, the differences were not significant by 2 months. The laser also offers a means of improving on existing technologies such as posterior capsulotomy, he said.

"Numbers to Prove It"

William Fishkind, MD, of the Eye Care and Surgery Center in Tucson, Arizona, who moderated the Femtosecond Cataract Session, noted that clinicians are "starting to generate numbers" showing better outcomes when using femtosecond lasers for cataract surgery.

"Last year our experience was 5 to 10 cases. Now we're looking at experience with 800 cases, and also seeing new applications, such as its use in pediatric cases," he said.

But Samuel Masket, MD, from Advanced Vision Care in Los Angeles, California, session comoderator, said, "We know laser surgery makes cataract surgery better, but does it make it easier? The real question has not been addressed, and that is, how do we transition cataract surgery?" During the year since his institution has had a femtosecond laser, he said that surgeons have indicated certain components of the surgery are actually more difficult.

Bruce Wallace, III, MD, of Wallace Eye Surgery in Alexandria, Louisiana, a panelist at the session, added that the reduction post-operative inflammation is an advantage for the patient. While laser surgery will cost more, he acknowledged, "We can discuss with patients that they may see better faster, and we have the numbers now to prove it."

Dr. Lawless is a member of the Alcon LenSx USA Medical Advisory Board. Dr. Dick reported relationships with Abbott Medical Optics, Bausch & Lomb, Novartis, and OptiMedica. Dr. Wallace reported relationships with Abbott Medical Optics, Bausch & Lomb, and LensAR. Dr. Fishkind reported relationships with Abbott Medical Optics and LensAR. Dr. Masket reported financial relationships with Alcon, Accutome, Bausch & Lomb Surgical, Haag-Streit, Ocular Theraputix, PowerVision, and Zeiss.

American Academy of Ophthalmology (AAO) and Asia-Pacific Academy of Ophthalmology 2012 Joint Meeting. Abstracts PA005 and PA006. Presented November 11, 2012.