Comment on: Femtosecond laser-assisted cataract surgery versus 2.2-mm clear corneal phacoemulsification.

Sir,

While congratulating the authors of “Femtosecond laser-assisted cataract surgery versus 2.2-mm clear corneal phacoemulsification” for elaborately comparing the outcomes of femtosecond laser-assisted cataract surgery (FLACS) with conventional method, we would like to bring to light certain points which we thought might be important in this context.[1]

The authors found that 1-month postoperative endothelial cell loss (ECL) was higher with FLACS with no difference in postoperative central corneal thickness (CCT), without mentioning the intergroup P value. We applied parametric statistics to arrive at the intergroup P = 0.58 comparing the final CCT at 4 weeks. However, a percentage change of CCT in each group with comparative statistics should have been mentioned to arrive at the abovementioned conclusion.

Although the authors have found a significantly higher ECL with FLACS, they have not mentioned the phacotorsional energy measured as cumulative dissipated energy which has significant effect on ECL apart from fluid usage or effective phaco time.[2] Phaco energy and time are the most important factors for endothelial damage, and FLACS may be beneficial by omitting need to sculpt and/or chop the nucleus, with similar results as studies comparing phaco chop with divide-conquer technique.[34] They have also not specified which mode of phacoemulsification was used; however, they did mention about the effective phaco time being lesser in FLACS (P < 0.001). The meta-analysis by Chen et al. did not find any reduction in ECL or CCT rise with FLACS as against one by Popovic et al. which found a significant reduction of ECL with no difference in surgical time.[5]

In addition, an analysis by grade of cataract may be undertaken to further analyze the ECL in the harder grades over the lower ones to finally conclude, in which group of patients FLACS may be effectively a better option. We await a response eagerly.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.