Comparing the efficacy and safety of femtosecond laser-assisted vs conventional penetrating keratoplasty: a meta-analysis of comparative studies

To investigate the safety and efficacy of femtosecond laser-assisted penetrating keratoplasty (FLAK) versus conventional penetrating keratoplasty (CPK). A literature search of PubMed, Cochrane, Embase, Web of Science, and Clinicaltrials.gov was conducted for comparative studies published from January 2007 to October 2019. Studies that involved both FLAK and CPK groups and reported on the relevant efficacy and/or safety parameters were included. The Newcastle–Ottawa quality assessment scale was used to analyse the methodological quality of these studies. Further, weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated. From the screened articles, a total of 1991 eyes from nine comparative studies were included. FLAK was not statistically superior for twelve-month postoperative best corrected visual acuity (WMD = − 0.06; 95% CI [− 0.16, 0.04]; P = 0.22), corneal astigmatism (WMD = − 0.81; 95% CI [− 1.63, 0.01]; P = 0.05) or six-month postoperative uncorrected visual acuity (WMD = − 0.11; 95% CI [− 0.27, 0.06]; P = 0.21). There were no significant differences in corneal graft rejection rate and the graft failure between FLAK and CPK at twelve months postoperative. However, best-corrected visual acuity (BCVA) and corneal astigmatism corrected with FLAK were better than those with CPK six months postoperative after elimination of data heterogeneity. Visual outcomes improvement in FLAK was better than that in CPK at six months postoperative, but not twelve months postoperative. This review recommends selecting a technique based on patients’ work demands and economic burdens.