Linda Roach

May 29, 2013

SAN FRANCISCO, California — Femtosecond laser-assisted cataract surgery in adults can be effective and safe in all types of eyes, including those with mature cataracts or comorbidities like Fuchs' dystrophy and pseudoexfoliation, according to a new study.

"If you look at the manuals for femtosecond lasers, many of these patients are excluded from femtosecond laser cataract surgery," said H. Burkhard Dick, MD, from Ruhr University Eye Hospital in Bochum, Germany.

In this prospective nonrandomized study in which 1 or more steps of cataract surgery was performed with a Catalys femtosecond laser (OptiMedica), the researchers did not exclude these patients.

Dr. Dick presented the results to a standing-room-only audience here at the American Society of Cataract and Refractive Surgery 2013 Symposium.

Prior to surgery, patient comorbidities were documented and cataracts were graded on the Lens Opacities Classification System (LOCS) III scale. The laser and phacoemulsification equipment were located in a single operating room, and sterile procedures were observed.

The researchers recorded all procedures on video. They assessed the quality and precision of capsulotomy, complications during and after surgery, and the effective phacoemulsification time required to remove the cataractous lens.

Pseudoexfoliation and Fuchs' dystrophy are good examples where the benefits are obvious.

Although 26% of the 850 patients had comorbidities, when lenses were prefragmented with the laser, the average amount of ultrasound energy needed to emulsify the lens fell by 96%, compared with phacoemulsification. "In the last 100 cases, we used no phaco at all," he noted.

In 16 eyes (1.9%), small capsular tags led to intraoperative difficulties with the capsulotomies. Of the affected patients, 9 were on anticoagulant therapy, 5 had small pupils, and 2 had eyes with mature cataracts, Dr. Dick reported. The capsulotomies were completed manually, with minimal effort and without capsular tearing.

No tags were seen in eyes with glaucoma, Fuchs' corneal dystrophy, cornea guttata, pseudoexfoliation, scars, previous vitrectomy, or intraoperative floppy iris syndrome.

The low incidence of complications is largely related to the fluid-cushioned docking mechanism on the laser, which does not applanate the cornea, Dr. Dick told Medscape Medical News.

"I have a lot of experience in eyes that could have been challenging but were possible because of the easy docking with this interface, he explained. "I am very confident in the technology and think it is one of the critical parts of the system design that allows me to treat all patients," such as those with different types of anesthesia, strabismus, pterygiums, blebs, iris hooks, and after pars plana vitrectomy with altered conjunctiva.

This study has highlighted certain advantages of laser cataract surgery, said Michael Lawless, MBBS, FRANZCO, FRACS, a corneal and refractive surgeon from Sydney, Australia.

"Bringing a femtosecond laser to cataract surgery should bring greater precision, reproducibility, and safety to all patients, but the quantum of improvement may be more in eyes with coexisting problems," Dr. Lawless explained. "Pseudoexfoliation and Fuchs' dystrophy are good examples where the benefits are obvious. Floppy iris syndrome is another; to have significant portions of the procedure completed prior to opening the eye is advantageous," he told Medscape Medical News.

Dr. Lawless and his team, who operate with the LenSx femtosecond laser (Alcon), recently reported outcomes for 1500 femtosecond laser-assisted cataract procedures (Ophthalmology. 2013;120:227-233).

He said they initially feared that the rise in intraocular pressure during docking would harm a glaucoma patient's compromised optic nerve or damage a filtering bleb. However, "this is no longer an issue with femto lasers that induce a small rise in intraocular pressure, such as the device used by Dr. Dick's team and the LenSx SoftFit docking mechanism we use. A liquid interface is not necessary for this purpose," he explained.

"Our current phaco handpieces and our current techniques are old technology and do not allow us to make the most of femto lasers," he added. "We are just at the beginning of the development of new instruments and settings that will take advantage of femto laser technology."

This study was funded by Ruhr University Bochum. Dr. Dick reports being a consultant for OptiMedica and several other ophthalmic companies, providing marketing and practice management advice to clinical ophthalmologists, and being a member of the OptiMedica medical advisory board. Dr. Lawless reports being a consultant for Alcon Laboratories, receiving travel support from Alcon, and being a member of the Alcon LenSx USA medical advisory board.

American Society of Cataract and Refractive Surgery (ASCRS) 2013 Symposium: Paper session 1-B. Presented April 20, 2013.


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