Comparison of efficacy of conbercept,aflibercept,and ranibizumab ophthalmic injection in the treatment of macular edema caused by retinal vein occlusion:a Meta-analysis

AIM:To evaluate and compare the anatomical and functional outcomes and negative effects of the three anti-vascular endothelial growth factor(VEGF)drugs in the treatment of macular edema(ME)due to retinal vein occlusion(RVO)based on the evidence pooled from current clinical trials and observational studies.METHODS:A systematic literature search was conducted on nine online databases from inception until April 30,2022.The main endpoints were best corrected visual acuity(BCVA),central macular thickness(CMT),and adverse events(AEs).Cumulative Meta-analysis was conducted to synthesize the outcomes of the drugs.The retrieved data were analyzed using Stata software(version 12.0).RESULTS:A total of 20 studies comprising 1674 eyes met the inclusion criteria to the Meta-analysis.It was observed that conbercept and aflibercept had better visual acuity effects compared with ranibizumab at 1mo[weight mean difference(WMD)=-0.03,P=0.001;WMD=-0.05,P=0.019],but the effects were not different from that of ranibizumab at 6mo.Moreover,there was not statistically significant dif ference in the propor tion of patients gaining≥15 letters at 12-24mo between aflibercept and ranibizumab[odds ratio(OR)=1.16,P=0.427].Conbercept had higher mean CMT change effects at 1mo(WMD=-14.43,P=0.014)and 6mo(WMD=-35.63,P≤0.001)compared with ranibizumab.Meanwhile,the mean CMT change effects at 1mo(WMD=-10.14,P=0.170),6mo(WMD=-26.98,P=0.140)and 12-24mo(WMD=-12.34,P=0.071)were comparable among the groups.Similarly,AEs were not significantly different among the treatments(OR=0.75,P=0.305;OR=1.04,P=0.89).The stability of effect size of mean BCVA and CMT improved with the increase in sample size.Aflibercept and conbercept required fewer injections compared with ranibizumab.CONCLUSION:This is the first study to evaluate the efficacy and AEs of intravitreal administration of conbercept,ranibizumab,and aflibercept in the treatment of RVOME.Intravitreal aflibercept or conbercept results in better mean change in vision and CMT reduction compared with ranibizumab.Conbercept can be considered to be a promising and innovative drug with good anti-VEGF effects.

Photon polarization effects in polarized electron–positron pair production in a strong laser field

Deep understanding of the impact of photon polarization on pair production is essential for the efficient generation of laser-driven polarized positron beams and demands a complete description of polarization effects in strong-field QED processes.Employing fully polarization-resolved Monte Carlo simulations,we investigate correlated photon and electron(positron)polarization effects in the multiphoton Breit–Wheeler pair production process during the interaction of an ultrarelativistic electron beam with a counterpropagating elliptically polarized laser pulse.We show that the polarization of e−e+pairs is degraded by 35%when the polarization of the intermediate photon is resolved,accompanied by an∼13%decrease in the pair yield.Moreover,in this case,the polarization direction of energetic positrons at small deflection angles can even be reversed when high-energy photons with polarization parallel to the laser electric field are involved.