A Comparative Study On The Efficacy Of Different Administration Regimens Of Ranibizumab In The Treatment Of Choroid Neovascularization Secondary To Pathological Myopia

ObjectiveTo compare the efficacy and injection numbers of different regimens of ranibizumab in the treatment of choroidal neovascularization secondary to pathologic myopia(PM-CNV),as well as the factors affecting retreatment.MethodsThis study is a retrospective control study.Forty-two patients(43 eyes)with PM-CNV diagnosed by fundus fluorescein angiography(FFA)in the Department of Ophthalmology of the first affiliated Hospital of Nanchang University from January2015 to January 2020 were enrolled in the study.According to the different administration regimens of intravitreal injection of ranibizumab,they were divided into 3+PRN group(group A)and 1+PRN group(group B).There were 22 cases(22eyes)and 20 cases(21 eyes)respectively.The dose of each intravitreal injection of ranibizumab was 0.05ml(10mg/ml),patients in group A patients received3-monthly ranibizumab as loading doses,while patients in group B received only single initial ranibizumab at baseline.After completing the initial treatment,patients in both groups were injected as needed according to the standard of retreatment.All patients underwent comprehensive ophthalmological examination before treatment,including best corrected visual acuity(BCVA),intraocular pressure,axial length,refractive error,slit lamp microscope,fundus photography,optical coherence tomography(OCT)and FFA.BCVA,central macular thickness(CMT),CNV thickness and intraocular pressure(IOP)were compared between the two groups at 1,3,6 and 12 months after treatment.The numbers of vitreous injection,retreatment rate and recurrence rate after initial treatment were compared between the two groups,and the related factors affecting retreatment were analyzed.Results1.Baseline data:there were no significant differences in age,gender,baseline BCVA,intraocular pressure,axial length,refractive error,CMT,CNV thickness,area of CNV and position of CNV between the two groups.2.Visual acuity and anatomical outcomes:(1)BCVA(Log MAR):The average BCVA in group A and group B increased significantly at 1,3,6 and 12 months after treatment,and the difference between BCVA at each follow-up time point and baseline was statistically significant(F time=40.55,P=0.000).BCVA showed the same trend over time in both groups(F interaction=1.53,P=0.212).At different time points,there was no statistically significant difference in average BCVA between group A and group B(F group=1.09,P=0.303).(2)CMT:The average CMT of group A and group B was significantly decreased at 1,3,6 and 12 months after treatment,and the difference between the CMT at each follow-up time point and the baseline was statistically significant(F time=25.67,P=0.000).The trend of CMT change over time was the same in both groups(F interaction=0.84,P=0.508).At different time points,there was no statistically significant difference in average CMT between group A and group B(F group=1.76,P=0.192).(3)CNV thickness:the average CNV thickness of group A and group B was significantly decreased at 1,3,6 and 12months after treatment,and the difference between the CNV thickness at each follow-up time point and the baseline was statistically significant(F time=33.81,P=0.000).The variation trend of CNV thickness over time was consistent in 2 groups(F interaction=2.30,P=0.077).At different time points,there was no statistically significant difference in average CNV thickness between group A and group B(F group=1.47,P=0.231).3.The number of injections and additional injections:during the 12 months of follow-up,the average number of injections in group A was 3.41±0.67,while that in group B was 1.95±1.12,the difference was statistically significant(u=65,P<0.001).The number of additional injections in group A and B were 0.41±0.67 and 0.95±1.12respectively,and there was no significant difference(u=161.5,P=0.061).4.Retreatment rate and recurrence rate:during the follow-up period,7 eyes(31.8%)of 22 patients in group A were treated with reinjection,while 12 eyes(57.1%)of 21 patients in group B were treated with reinjection.There was no significant difference in the retreatment rate between the two groups(χ~2=2.79,p=0.095).Recurrence occurred in 3 eyes(13.6%)in group An and 6 eyes(28.6%)in group B.there was no significant difference in recurrence rate between the two groups(P=0.281).5.Related factors affecting retreatment:1+PRN regimen(HR=7.569,p=0.006),female(HR=9.417,p=0.013),baseline CMT>300μm(HR=6.258,p=0.039)and baseline CNV area>1.0mm~2(HR=7.634,p=0.025)are important risk factors for retreatment.6.Complications:during the 12 months of follow-up,only one eye in group A had transient high intraocular pressure at the first month of follow-up,and the intraocular pressure of the other patients was in the normal range.No serious complications such as cataract,endophthalmitis,retinal hole and retinal detachment occurred in all patients.Conclusions1.The two regimens of intravitreal injection of ranibizumab treatment can effectively improve the vision of PM-CNV patients and reduce the CMT and thickness of CNV with good safety.2.Compared with the 3+PRN regimen,the total injection numbers of the 1+PRN regimen were less under the premise of similar efficacy,which reduced the treatment risk and cost.3.1+PRN regimen,female,baseline CMT>300μm,baseline CNV area>1.0mm2are important related factors of retreatment.