Concentration Of VEGF And Bevacizumab In Aqueous Humor In Age-related Macular Degeneration After Intravitreal Bevacizumab Injection

Objective: To investigate the changes in VEGF and Bevacizumab levels in aqueoushumor after intravitreal bevacizumab injections in eyes with age-related maculardegeneration (AMD) and to compare with changes in central macular thickness (CMT)and visual acuity (VA) to select the retreatment time.Methods: Aqueous samples were collected in the First Affiliated Hospital of the DalianMedical University between November2012and March2013. Aqueous samples frompatients of Cataract were collected as the control group. All AMD patients receivedintravitreal bevacizumab (1.25mg/0.05ml) injections. After the first injection all patientswere divided into to4groups. Patients who received the second injection4weeks laterwere categorized as Group A. Similarly, patients who received the second injectionafter6weeks were categorized as Group B; after8weeks were categorized as Group Cand after10weeks were categorized as Group D. The concentration of unboundbevacizumab and VEGF were measured by enzyme-linked immune sorbent assay.Results:The aqueous humor level of VEGF in AMD group was higher than controlgroup. In the AMD group, mean±standard deviation(SD) aqueous VEGF levels were(158.56±73.94) pg/ml.The VEGF concentration in control group was (72.03±31.03)pg/ml (P=0.010, P<0.05). After the injections the concentration of VEGF in aqueouswere decreased. The mean±standard deviation(SD) aqueous VEGF level was(16.8±6.75)pg/ml in Group A,(24.05±8.45)pg/ml in Group B,(54.25±19.50)pg/ml inGroup C and (69.04±28.61)pg/ml in Group D. The difference in VEGF levels in GroupA and B, C and D was not statistically significant(P=0.378; P=0.070, P>0.05). After theinjections the concentration of bevacizumab were different in different group. The mean±standard deviation(SD) aqueous level of bevacizumab was (7200.77±2838.95)pg/mlin Group A,(917.38±420.55)pg/ml in Group B,(172.49±96.37)pg/ml in Group C,(21.38±18.21)pg/ml in Group D. All groups had statistically significant difference inconcentration of Bevacizumab. The CMT was significantly reduced after the first intravitreal bevacizumab injection. The mean±standard deviation(SD) of CMT inGroup A was (255±49)μm, Group B was (241±42)μm, Group C was (256±36)μmand Group D was (263±56)μm. Each group didnot not have a statistically significantdifference (P=0.742, P>0.05). There was also no statistically significant difference inVA(LogMAR) in each group (P=0.362, P>0.05). The mean±standard deviation(SD) ofVA in Group A was (0.68±0.24), Group B was (0.61±0.25), Group C was(0.62±0.30)and Group D was (0.62±0.22)μm.Conclusions:1. The VEGF in aqueous humor of AMD patients were significantlyhigher than normal.2.Its an effective and safe treatment method to AMD.3.Theconcentration of bevacizumab and VEGF in aqueous humor levels were negativelycorrelated.4.6to7-weeks intervals may be appropriate in treating AMD withbevacizumab.