Femtosecond lasers produce similar results

November 9, 2008

A study of two femtosecond lasers (IntraLase FS60, Advanced Medical Optics; Zeimer LDV, Ziemer Ophthalmic Systems) found that both lasers produced very similar results at all time points examined after LASIK, according to Dan Durrie, MD.

A study of two femtosecond lasers (IntraLase FS60, AdvancedMedical Optics; Ziemer LDV, Ziemer Ophthalmic Systems) found thatboth lasers produced very similar results at all time pointsexamined after LASIK, according to Dan Durrie, MD.

He and his colleagues conducted a contralateral head-to-headstudy that included 38 eyes of 19 patients. One laser was used inone eye and the other laser in the other eye of each patient. Alleyes had the same flap size and superior hinges; one surgeonperformed all procedures. The investigators evaluated high- andlow-contrast acuity, wavefront analysis, optical coherencetomography and confocal microscopy findings, and patientsatisfaction.

There were very slight differences in the procedures using thetwo lasers; however, the results were remarkably similar.

"Both lasers make good flaps," Dr. Durrie said. "The visualacuity (VA) results and the safety of both were excellent. The VAresults were similar at 1 day, 1 week, 1 month, and 3 months; theaccuracy of the refractions also was similar. There were nostatistical differences between the groups in the manifestrefraction spherical equivalent, residual cylinder, the flapthickness, and the uniformity."

There was also less debris in the interfaces seen on imaging andmicroscopy, he said.

At the beginning of the procedures, the magnifications differedbetween the two lasers. The difference with the IntraLase, Dr.Durrie said, is that the surgeon puts the suction ring on, movesover to the laser, and docks the cone and the suction ring. Withthe LDV laser, these functions are all on a single hand piece andall those functions occur at about the same time, he explained.The visibility is not the same as with the IntraLase and themanufacturer is working on putting a camera under the head.Another slight difference is that the flap edges need to bemarked.

The only complications that developed were an epithelial defectin one patient, and a slipped flap and epithelial ingrowth in thesame patient. Dr. Durrie attributed these to the learning curvewith the LDV laser.

The patients reported that the VA returned faster 1 hour aftersurgery with the Ziemer LDV; when measured objectively, the VAwas about the same in both groups at that time point.