Laird Harrison

April 22, 2015

SAN DIEGO — Refractive outcomes and the difference in best corrected visual acuity in patients treated with conventional cataract surgery are not significantly different than those in patients treated with femtosecond laser-assisted surgery, a new study shows.

Advocates claim that femtosecond laser-assisted surgery is more precise, safer, and more efficient than conventional surgery, said Kendall Donaldson, MD, from the Bascom Palmer Eye Institute in Plantation, Florida.

Conventional cataract surgery leaves a lot to be desired, she pointed out, because more than half of manual cataract surgeries leave a residual refractive error of more than half a diopter.

However, several studies have found little difference in visual acuity or complications between conventional and femtosecond laser-assisted surgery.

"We have to be careful what we promise our patients," said Dr Donaldson, who presented study results here at the American Society of Cataract and Refractive Surgery 2015 Symposium.

Dr Donaldson and her colleagues retrospectively analyzed 621 eyes in 509 patients whose cataracts were treated with either conventional or femtosecond laser-assisted surgery at Bascom Palmer. Patients with toric lenses were excluded from the analysis.

Femtosecond surgery involved either the Catalys precision laser system (Abbott Medical Systems) or the LenSx laser system (Alcon).

Rates of refractive error were not statistically different in the three treatment groups.

Table 1. Refractive Outcomes in the Three Surgery Groups

Diopter Conventional, % Catalys, % LenSx, %
≤0.25 31 29 29
≤0.5 50 53 53
≤1.0 74 77 80


Fewer patients treated with conventional than with the laser surgery attained vision of at least 20/20 (62% vs 100%) or at least 20/40 (80% vs 98%), but the difference in best corrected visual acuity was not significantly different.

In a separate analysis of 74 eyes in 42 patients who received toric intraocular lenses for astigmatism, there was a trend toward the superiority of laser surgery over conventional surgery, but the difference was not significant.

Table 2. Refractive Outcomes in Patients With Toric Intraocular Lenses

Diopter Conventional, % Laser, %
≤0.25 38 59
≤0.5 71 79
≤0.75 71 84


Dr Donaldson concluded that it is still not clear whether femtosecond laser-assisted surgery is better than conventional surgery for cataracts.

"It's great to see studies" comparing the two approaches, said session panelist Richard Davidson, MD, from the University of Colorado in Aurora.

However, these short-term studies do not give a complete picture. "They did not look at things like epithelial cell loss that can have a long-term effect," he told Medscape Medical News.

Previous studies have shown less epithelial cell loss after laser surgery, he said, but lasers have only been in use for about 4 years. It could take 10 or 15 years to know whether such effects are clinically significant.

"It would be helpful to be able to tell patients, 'Your vision may not be better, but we'll probably save more cells in your cornea.' That could be beneficial down the road," said Dr Davidson.

Dr Donaldson has disclosed no relevant financial relationships. Dr Davidson reports a financial relationship with Alcon.

American Society of Cataract and Refractive Surgery (ASCRS) 2015 Symposium. Presented April 18, 2015.


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