Femto versus phaco

Meta-analysis shows safety and efficacy advantages of FLACS compared 
to conventional cataract surgery

Default banner image for Femto versus phaco
Photo of Roibeard O’hEineachain

Femtosecond laser-assisted cataract surgery (FLACS) appears to provide better uncorrected visual acuity and significantly less endothelial cell loss compared to conventional cataract surgery, according to a meta-analysis of peer-reviewed studies comparing the two techniques, said Thomas Kohnen MD, PhD, FEBO, Department of Ophthalmology, Goethe University Frankfurt, Germany. The analysis also indicated that FLACS poses no additional dangers to the eye apart from a slightly but significantly higher incidence of anterior capsule rupture. The findings contradict those of other authors which have suggested that FLACS may entail a higher risk of posterior capsule rupture than conventional surgery, Prof Kohnen told the 21st ESCRS Winter Meeting in Maastricht, The Netherlands. “FLACS has a similar complication profile to conventional cataract surgery but seems to be superior in critical areas like loss of endothelial cell density. Furthermore, in one of the main areas where FLACS is said to be inferior, higher rate of posterior capsular rupture, we could not find any significant difference between the two methods,” he said. Prof Kohnen and his associates included 42 peer-reviewed prospective and retrospective studies published until September 2016 in their meta-analysis. They identified the studies through a systematic review of Medline, Cochrane Library and Embase according to PRISMA guidelines. The meta-anlaysis comprised a total of 9,400 eyes that underwent FLACS and a total of 8,779 eyes that underwent conventional cataract surgery with ultrasound phacoemulsification and manual incisions and capsulotomies. All of the studies compared the two cataract surgery approaches, each recording their own set of parameters. BETTER VISION, BETTER SAFETY The researchers found that, in terms of mean uncorrected visual acuity, FLACS-treated eyes had significantly better outcomes than conventionally treated eyes at last visit (p=0.05), in five trials reporting the outcome parameter, which involved a total of 3,240 eyes. In addition, there was a non-significant trend in favour of FLACS-treated eyes towards better corrected visual acuity in five studies involving 1,472 eyes (p<0.0001). Furthermore, overall endothelial cell loss after three months was significantly lower in the FLACS-treated patients than in those undergoing conventional cataract surgery (P<0.01) in five trials involving 1,335 eyes. Central corneal thickness was also lower among FLACS-treated eyes at one day (p=0.00010) and one month (p=0.02) after surgery compared to those undergoing conventional surgery. Prof Kohnen noted that capsulorhexis circularity was achieved to a significantly greater extent in the FLACS-treated eyes than in conventionally treated eyes in six studies involving 966 eyes (p=0.0001). On the other hand, anterior capsule rupture occurred in 37 (1.4%) of 2,516 FLACS-treated eyes compared to only eight (0.27%) of 2,863 conventionally-treated eyes. With both techniques, most of the anterior ruptures occurred in one study. However, contrary to the conclusion of some authors, Prof Kohnen and his associates found that FLACS did not raise the risk of posterior capsule rupture compared to conventional surgery. Overall, there were 11 posterior capsule ruptures among 3,451 eyes undergoing FLACS, and 16 among 3,883 eyes undergoing conventional cataract surgery (p=0.27). He added that, although a recently published meta-analysis (Popovic et al, Ophthalmology 2016;123(10):2113-26) found a significantly greater incidence of posterior capsule ruptures in FLACS-treated eyes, he and his associates found no significant differences between the two approaches in terms of the complication when the results of non-comparative studies were eliminated from the analysis. Thomas Kohnen: 
kohnen@em.uni-frankfurt.de
Tags: FLACS