Application Of OCTA In The Differenct Of Responses To Anti-VEGF Therapy Between Treatment-Naive And Treated NAMD Patients

Purpose Optical coherence tomography angiography(OCTA)was used to observe the differenct of responses to anti-vascular endothelial growth factor(VEGF)therapy between treatment-naive and treated neovascular age-related macular degeneration(nAMD)patients.Methods A total of 55 patients with nAMD diagnosed by fundus fluorescein angiography in Zhejiang Provincial people’s Hospital from October 2019 to December 2020 were collected,including 35 patients who had not received any intervention treatment for choroidalneovascularization(CNV)as the experimental group.A total of 20 patients with recurrent nAMD who had received standard pro re nata(PRN)treatment in the past six months were included in the control group,which matched age,sex,eye condition and general condition.Patients need to be injected into the vitreous cavity once a month for 3 months.The best corrected visual acuity(bestcorrectedvisualacuity,BCVA),OCT and OCTA were recorded on the same day before operation and 2 weeks after operation.The CNV features and the blood perfusion characteristics of retina and choroid on OCTA images were compared between the two groups,and statistical analysis was carried out.Results 1.Three times in the experimental group after 2 weeks of treatment area of CNV,vascular density,maximum linear dimension(greatestlineardimension,GLD)were significantly reduced compared with preoperative(P<0.05),after the third treatment of CNV area,the density of blood vessels,GLD is baseline decreases and was statistically significant(F=0.533,P=0.000;F=23.954,P=0.000;F=1.314,P=0.000);In the control group,the vascular density of CNV at 2 weeks after the three treatments was decreased compared with that before the operation,with statistical significance(P<0.05).In the control group,the CNV area at 2 weeks after the three treatments was decreased compared with that before the operation,but there was no significant difference(P>0.05).Two weeks after the three treatments,GLD was lower than that before the surgery,but the difference was significant only for the second treatment(P=0.078,0.000,0.505).2.Three times in the experimental group after 2 weeks of treatment of choroid empty area(Choroidalflowvoidarea CFVA)preoperative area were significantly decreased(P<0.05),after the third treatment CFVA than baseline area is reduced and was statistically significant(F=0.999,P=0.000).In the control group,the CFVA area decreased 2 weeks after the three treatments(P>0.05).3.Experimental group in three treatment after 2 weeks of shallow vein complex(SuperficialVascularComplex,SVC)layer density compared with preoperative blood flow were significantly decreased(P<0.05),after the third treatment of SVC layer flow density increase from the baseline and was statistically significant(F=0.123,P=0.000).In the control group,the blood flow density in the SVC layer decreased significantly from baseline after the third treatment(F=0.297,P=0.009).The blood flow density in the DeepVascularComplex(DVC)layer of the experimental group was decreases 2 weeks after the th-ree treatments(P>0.05),while that in the control group was decreased 2 weeks after the three treatments(P=0.964,P=0.004,P=0.124).4.The blood flow density of the Choriocapillaris(CC)layer in the experimental group and the control group decreased at 2 weeks after the three treatments(P=0.338,P=0.028,P=0.055)and 2 weeks after the three treatments(P=0.028,P=0.163).5.In the experimental group,the blood flow density in the Choroid(C)layer 2 weeks after the second treatment was significantly increased compared with that before the operation(P=0.0043),and the blood flow density in the C layer 2 weeks after the first and third treatment was decreased compared with that before the operation,but there was no statistical significance(P=0.054,P=0.065).Control group in the first and second treatment two weeks after the C layer of density compared with preoperative blood flow down slightly,but no significant difference(P=0.515,P=0.315),the third treatment of postoperative 2 weeks there is a decrease in the C layer density compared with preoperative blood flow,and have statistical significance(P=0.006),after the third treatment C layer flow density is slightly elevated baseline,but no statistical significance(F=3.818,P=0.518).6.The vascular density and BCVA of SVC layer were negatively correlated with central retinal thickness(CRT)in experimental group(rp=-0.352,P=0.038;rp=-0.212,P=0.000),CNV area,CNV vessel density,GLD,CFVA,DVC layer vessel density,CC layer vessel density,C layer vessel density had no correlation with CRT(rp=-0.091,P=0.605;rp=0.261,P=0.129;rp=-0.030,P=0.865;rp=0.235,P=0.175;rp=0.038,P=0.828;rp=0.118,P=0.500;rp=0.143,P=0.143,);CFVA in control group was positively correlated with CRT(rp=0.458,P=0.049),while vascular density and BCVA in CC layer were negatively correlated with CRT(rp=-0.489,P=0.033;rp=-0.294,P=-0.000),CNV area,CNV vascular density,GLD,SVC vascular density,DVC vascular density,C vascular density had no correlation with CRT(rp=0.569,P=0.111;rp=-0.038,P=0.878;rp=0.286,P=0.236;rp=-0.304,P=0.206;rp-0.132,P=0.590;rp=0.402,P=0.088).Conclusion 1.In OCTA,patients initially treated with NAMD can dynamically observe CNV area,CNV vascular density,GLD and CFVA.Patients treated with NAMD can change according to the vascular density of CNV.The decrease of these indexes can indicate the response of patients against VEGF,while the increase may indicate the recurrence of CNV,which can be used to guide clinical follow-up.2.The decrease of blood flow density in SVC layer and DVC layer confirmed that retinal microcirculation was affected by anti-VEGF treatment.NAMD-nAMD SVC in patients treated first layer flow density is more sensitive indicators,for the cure patients DVC layer density change is suspicious of observation indexes,blood flow can be used to observe changes of retinal blood supply,but still needs more research to prove that the anti VEGF treatment affect the relationship between blood supply and retinal atrophy,provide a new direction to predict nAMD-nAMD progress.3.Previously,CRT was a monitoring index for NAMD patients during follow-up.Correlation analysis showed that patients initially treated with NAMD could quantitatively measure the vascular density in the SVC layer.Patients treated with NAMD could use the vascular density in the CFVA and CC layer to observe the disease development and determine the timing of re-anti-VEGF treatment,which could improve the clinical monitoring standard.