Meta analysis of deep lamellar keratoplasty and penetrating keratoplasty for keratoconus

Abstract

Background Nowadays,keratoplasty is widely used in the treatment of keratoconus.Deep lamellar keratoplasty(DLKP)is one of the research hotspots.However,its effacacy and safety are still concerned.Objective This paper was to evaluate and compare the therapeutic outcomes between DLKP and penetrating keratoplasty(PKP) for keratoconus.Methods The peer-reviewed and published literature was searched from PubMed database,Cochrane Library,EMBase and CNKI to identify relevant trails comparing DLKP with PKP for keratoconus.Methodological quality and Meta-analysis were carried out according to the principle of evidence-based medicine.The statistical analysis was performed using Review Manager 5.0 software.Results Eleven studies with 2950 eyes were identified that compared the results of DLKP and PKP procedures for keratoconus directly.Of those studies reporting vision and refractive data,less patients underwent DLKP achieved a best corrected visual acuity (BCVA)of≥0.5 than DLKP(RR=0.91,95％ CI:0.84-0.99,P=0.030) ;patients with DALK had severer myopia that those with PKP(RR =-0.60,95％ CI:-1.43-0.23,P =0.150),but the astigmatism was comparative (WMD =0.21,95％ CI:-0.48-0.91,P =0.550).Endothelial cell density values were higher in the DLKP group and the differences were significant.Endothelial immune graft rejection did not occur after DALK,and PKP had a higher overall graft rejection rate than DLKP(RR=0.06,95％ CI:0.01-0.31,P=0.001).Conclusions According to the available data,PKP can imporve the BCVA and refractive results,but DLKP can avoid the risk of endothelial rejection and reduce the risk of late endothelial failure for keratconus. Key words: Keratoconus; Deep lamellar keratoplasty; Penetrating keratoplasty; Evidence-based medicine; System review/Meta analysis