| Part ⅠComparison of Conbercept with Ranibizumab for the Treatment of Macular Edema Secondary to Branch Retinal Vein Occlusion[Background]Branch retinal vein occlusion(BRVO)was reported to be the second most common fundus disease after diabetic retinopathy.Macular edema(ME)secondary to branch retinal vein occlusion(BRVO)is a major cause of vision loss.Appropriate and timely treatment of ME can prevent structural impairment and improve visual acuity(VA).Currently using anti-VEGF therapy has become the first-line treatment strategies of for the treatment of ME caused by BRVO.The main anti-VEGF reagents are ranibizumab and conbercept in our country.Ranibizumab(Lucentis;Genentech,Inc.,South San Francisco,CA,USA)is a monoclonal antibody fragment(Fab)that binds VEGFA.Ranibizumab has been approved for the treatment of ME secondary to BRVO.Conbercept,a novel anti-VEGF reagent,is a humanized,soluble,VEGF receptor(VEGFR)protein comprising extracellular domain-2 of VEGFR-1,and extracellular domains-3 and-4 of VEGFR-2.The most notable characteristic of conbercept is that it binds not only VEGF-A,but also VEGF-B,VEGF-C,and placental growth factor(PIGF)—all with high affinity.Furthermore,the affinity of conbercept to VEGF-A is even greater than that of ranibizumab.However,there are few reports regarding conbercept for treatment of BRVO-induced ME and there are no reports regarding the differences between conbercept and ranibizumab for treatment of BRVO-induced ME.The aim of this prospective study was to validate the therapeutic efficacy of conbercept for the treatment of ME secondary to BRVO by comparing with ranibizumab[Purpose]To confirm the therapeutic efficacy of conbercept for the treatment of macular edema(ME)secondary to branch retinal vein occlusion(BRVO)by comparing with ranibizumab.[Methods]This was a prospective,randomized,comparative study.This study examined 35 eyes(35 patients)with ME secondary to BRVO who were recruited between April 2015 and April 2016.Patients were randomized and divided into conbercept(n=18)and ranibizumab(n=17)groups.After an initial intravitreal injection of either conbercept or ranibizumab,a pro re nata(PRN)strategy was adopted based on loss of visual acuity(VA)or increase in central macular thickness(CMT).The interval of injections was not less than 4 weeks.The follow-up time was 6 months.[Results]Baseline characteristics did not differ significantly between the two groups.In conbercept group,the mean visual acuity was 0.67± 0.371ogMAR at baseline,mean BCVAs were 0.278±0.22,0.328±0.28,0.41±0.35,0.33±0.31,0.38±0.32,and 0.28±0.28 logMAR at months 1-6,respectively;Significant improvements in vision were observed at each follow-up visit compared with baseline values(p<0.05).The mean central macular thickness at baseline was 512.5±115.22μm at baseline,mean CMTs were257.94±55.22,327.44±137.09,336.38±136.10,274.72±88.09,292.22±118.6,and 250.06±76.32μm at months 1-6,respectively;significant improvements in CMT were observed at each follow-up visit compared with baseline values(p<0.05).In ranibizumab group,the mean baseline BCVA was 0.511±0.234logMAR at baseline,mean BCVAs were 0.218±0.159,0.253±0.197,0.247±0.265,0.229±0.320,0.241±0.312,and 0.247±0.330 logMAR at months 1-6,respectively;significant improvements in vision were observed at each follow-up visit compared with baseline values(p<0.05).The mean central macular thickness at baseline was 491.23±14.72μm,mean CMTs were 271.06±46.90,275.94±83.6,330.06±181.18,268.88±78.09,292.00±90.40,and 288.64±123.22 μm at months 1-6,respectively;significant improvements in CMTs were observed at each follow-up visit compared with baseline values(p<0.05).No significant differences in either improvement of BCVA(p>0.05,t-test)or reduction of CMT(p>0.05,t-test)was noted in either group.Mean numbers of injections were 2.28±0.96 and 2.65±1.17 for the conbercept and ranibizumab groups,respectively(p=0.478),with no statistically significant differences between the two groups.[Conclusion]Intravitreal injection of conbercept is shown to be safe and effective for the treatment of ME secondary to BRVO,based on 6-mo follow-up data.Part ⅡOne-year Outcome of Conbercept Therapy for Diabetic Macular Edema[Backgroud]Diabetic macular edema(DME)is the major cause of central visual loss.Vascular endothelial growth factor(VEGF)is an important regulator of vascular permeability in diabetic macular edema.Anti-VEGF drugs can not only effectively reduce macular edema,prevent further decrease of vision,but more importantly can further improve the visual acuity of patients,and now it has become the first-line treatment of DME.Dugel reported that baseline visual acuity was a strong factor to predict visual acuity gain in patients with diabetic macular edema following anti-vascular endothelial growth factor treatment.Another study reported that aflibercept had greater effect on the DME patients with worse baseline VA.When the initial VA was less than 69 letters,the change of VA from baseline to 1 year was the 18.9±11.5 letters,when the initial VA was from 69 to 78 letters;the change of VA from baseline to 1 year was the 8.0±7.6 letters.Conbercept,a novel reagent of anti-VEGF,is a humanized,soluble,VEGFR protein which blocks all isoforms of VEGF-A,VEGF-B,VEGF-C,and PIGF.Conbercept is similar to aflibercept in structure but they differ in that conbercept contains a fourth VEGFR-2 binding domain.Conbercept has been approved to treat neovascular AMD by the China Food and Drug Administration in December 2013.However,there is no report about the efficacy of conbercept for the treatment of diabetic macular edema with different baseline BCVA levels.[Purpose]To evaluate the therapeutic efficacy of conbercept for the treatment of diabetic macular edema(DME)with different baseline visual acuity.[Methods]This is a prospective,comparative study.This study examined 50 eyes(50 patients)with DME who were recruited between January 2014 and April 2016.According to the baseline best corrected visual acuity(BCVA),the patients were assigned into two groups.Eyes with baseline BCVA less than 69 letters were assigned into worse baseline VA subgroup,eyes with baseline BCVA of 78 to 69 letters were assigned into better VA subgroup.After one initial intravitreal injection,a pro-re-nata strategy was adopted based on the visual acuity loss or an increase of central macular thickness(CMT).The interval of injections was not less than 4 weeks.The follow-up time was 12 months.[Results]All patients finished the 12-month follow up.At baseline,best corrected visual acuity(BCVA)was 31.95±6.60 letters in worse baseline VA subgroup and 69.44±0.51 letters in the better baseline VA subgroup(p = 0.000).The baseline of CMT was 498.32±108.08μm in worse baseline VA subgroup and 397.67±71.79μm in better baseline VA subgroup(p = 0.002).At baseline,the BCVA and CRT were significantly different between the worse baseline VA subgroup and the better VA subgroup.At the end of twelve month follow up,BCVA was 49.263±11.916 letters in worse baseline VA subgroup and 72.67±2.83 letters in the better baseline VA subgroup Significant improvements of BCVA was observed compared to that of baseline(p<0.05).At the end of twelve month follow up,CMT was 280.05±65.72 μm in worse baseline VA subgroup and 282.50±49.53μm in the better baseline VA subgroup.Significant decrease of CMT was observed compared to that of baseline(p<0.05).The mean improvement in the BCVA was 17.32±11.16 letters,7.28±2.05 letters for the worse baseline VA subgroup and better baseline VA subgroup,respectively.The mean decrease in CMT from baseline was218.26±130.93 μm,115.17±105.37μm for the worse baseline VA subgroup and better baseline VA subgroup,respectively.A significant difference was observed in term of the mean improvement of BCVA and decrease of CMT between the two groups.For the worse baseline VA,BCVA improvement and CMT decrease were more than that of better VA subgroup(p<0.05).The median numbers of injections were 7.05±0.911,6.28±1.07 for the worse baseline VA subgroup and better baseline VA subgroup,respectively(P=0.123,t-test),there were no statistically significant difference in number of injects between two groups.[Conclusion]In conclusion,conbercept is effective in the treatment of DME at different levels of baseline BCVA.The mean BCVA gains were negatively correlated to baseline BCVA.For the worse baseline VA,BCVA improvement was more than that of better VA subgroup. |
