OCTA Was Used To Evaluate The Effect Of Anti-VEGF Therapy In NAMD Patients And The Concentration Of Brain-derived Neurotrophic Factor And Beta-amyloid Protease-42 In Aqueous Humor Of NAMD Patients

Background Age-related macular degeneration(AMD)is the leading cause of irreversible visual impairment in the elderly,with its incidence increasing with age.As the cause of AMD is unknown,there are no specific drugs or fundamental preventive measures for the treatment of AMD except some supportive therapies.In addition,with the development of aging population,the prevalence of AMD increases year by year,so the research on the pathogenesis of AMD and the research and development of therapeutic drugs are urgent.Alzheimer's disease(AD)is a neurodegenerative disease of the central nervous system(CNS).Currently known molecular pathology related to AD includes amyloid?(A?),the major component of senile plaques,and tau protein,which is highly phosphorylated,the major component of neuronal fiber tangles.In recent years,a large number of studies have found that AMD and AD are both age-related diseases and have similar environmental risk factors,so the research on the correlation between the two has become a hot issue.In this study,we observed the efficacy of three consecutive anti-vascular endothelial growth factor(anti-VEGF)treatments in patients with neovascular macular degeneration(n AMD)by optical coherence tomography angiography(OCT-A).Then,this study based on neovascular AMD(n AMD)aqueous humor in patients with brain-derived neurotrophic factor(BDNF)and A? 42 test,to explore the pathogenesis of AMD,looking for new way of clinical treatment of AMD.In addition,the detection of cytokines in aqueous humor maybe used to assist clinical diagnosis of early AD.Part 1Purpose: An observation on the efficacy of three consecutive anti-vascular endothelial growth factor(anti-VEGF)treatments in patients with neovascular macular degeneration(n AMD)by optical coherence tomography angiography(OCTA).Methods: Twenty-three eyes with n AMD were treated with intravitreal injections(IVIs)of anti-VEGF once a month for three consecutive months.There were eight follow-up times: before the initial IVI and on days 1,3,7,14,30,60,90 after IVI.The content of the follow-up examinations consisted of best corrected visual acuity(BCVA),the height of retinal pigmented epithelium detachment(RPED),the greatest linear dimension(GLD),choroidal neovascularization(CNV).Results: BCVA gradually improved after IVI and improved significantly on day90(P=0.01).RPED improved after IVI,with a significant improvement on day 60(P=0.04,both eyes),but increased slightly on day 90.The GLD and CNV flow area gradually shortened in the early stage after IVI but rebounded on days 60 and 90.BCVA was positively correlated with RPED,GLD,and CNV flow area(r=0.26,P=0.001;r=0.36,P<0.001;r=0.26,P=0.001;r=0.24,P=0.002).Conclusion: 1.OCT-A provides advantages(non-invasive,convenient and patient compliance)for observation of CNV changes in each anti-VEGF treatment.2.OCT-A is an important reference and method for quantifying the therapeutic changes of n AMD against VEGF.Part 2Purpose:To determine brain-derived neurotrophic factor(BDNF)levels in the aqueous humor of patients with neovascular age-related macular degeneration(n AMD)and its correlation with retinal nerve fiber layer(RNFL).Methods: A total of 41 patients consisting of 21 n AMD patients and 20 control patients were included in the study.Patients with n AMD were scheduled to receive three doses of an intravitreal ranibizumab injection monthly.A cytometric bead array was used to detect BDNF expression in the aqueous humor,BCVA tests were conducted using the Snellen chart(20 feet),and optical coherence tomography angiography(OCT-A)was used to observe parameters of the retina.Cognitive function of all patients was assessed by mental state examination scale(MMSE)and Montreal cognitive assessment scale(Mo CA).Results: BDNF levels in the aqueous humor were found to be significantly lower in the n AMD group(0.67±0.16 pg/m L;0.70±0.20 pg/m L;0.67±0.16 pg/m L)than in the control group(1.81±1.23 pg/m L,P<0.001),and there was no statistically significant difference among the three measurements of the BDNF level from the aqueous humor of the n AMD group.In n AMD patients,the expression of BDNF was positively correlated with BCVA(r=0.81,P<0.001)and RNFL thickness(r=0.88,P=0.01).Conclusions:1.The expression of BDNF in aqueous humor decreased in patients with n AMD,which was correlated with patients' RNFL and visual acuity.2.Whether BDNF is involved in AMD is need to be further studied.Part 3Purpose:To determine amyloid ? 42(A? 42)level in aqueous humor of patients with neovascular age-related macular degeneration(n AMD)and its correlation with n AMD.Methods:A total of 70 patients were enrolled in this study,including 50 n AMD patients in the experimental group and 20 cataract patients in the control group.Patients with n AMD received intravitreal injection of renizumab and extraction of aqueous humor at the same time.Patients in the control group extractied aqueous humor at the same time during phacoemulsification.The expression of A? 42 in the aqueous humor was detected by cytometric bead array,Snellen chart shown the best-corrected visual acuity(BCVA),the mental state examination(MMSE)and Montreal cognitive assessment scale(Mo CA)assessment of all patients with cognitive function.Results:The cognitive function of 50 patients with n AMD was tested,and the patients with n AMD were divided into n AMD with cognitive impairment group 32 patients(cognitive impairment group)and n AMD without cognitive impairment group 18 patients(pure n AMD group).The expression of A? 42 in the cataract group(82.94±33.75 pg/m L)was significantly lower than that in pure n AMD group(136.42±51.68 pg/m L,P=0.01)and cognitive impairment group(117.90±34.46 pg/m L,P=0.01).Compared with the pure n AMD group,there was no statistically significant difference in the expression of A? 42 in the cognitive impairment group(P= 0.14).Analysis of correlation between aqueous humor A? 42 and BCVA,MMSE and Mo CA in the pure n AMD group showed that A? 42 was positive correlated with BCVA(r=0.54 P=0.02),but not significantly correlated with MMSE and Mo CA.Conclusions:1.The increased level of A? 42 in aqueous humor of nAMD patients is correlated with BCVA of patients,and its specific mechanism needs further study and discussion.2.Whether the expression level of A? 42 in aqueous humor can assist the clinical diagnosis of early AD needs further study.