Abstract
Purpose :
Vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang2) have been described in the pathogenesis of exudative macular degeneration (eAMD). This study measures the levels of VEGF and Ang2 in aqueous samples, collected at the time of each intravitreal injection for the treatment of eAMD. It also correlates the levels of VEGF with central macular thickness (CMT)
Methods :
Patients with eAMD undergoing treatment with intravitreal injections of anti-VEGF agents were included in the study. At each injection, paracentesis was done to equalize the intraocular pressure and the aqueous sample thus obtained was used for analyses. For controls, aqueous was collected from patients undergoing cataract extraction, without any other retinal pathology. Samples were immediately stored in -800 C freezer. For analysis, aqueous samples were thawed at room temperature. VEGF and Ang2 levels were measured using human premixed multi-analyte kit on Luminex MAGPIX analyzer (Austin, TX, USA). SD-OCT was obtained at each visit before the injection and CMT was measured. Only those samples were considered for analyses where there was no break of more than 3 months between the collection of samples. The VEGF levels, Ang2 levels and the CMT measurements obtained at the time of the most recent injection were compared to the baseline levels. The VEGF levels in all samples were also compared with CMT
Results :
300 samples from 36 patients (45 eyes) were analyzed, who received a minimum of 2 injections. The mean number of injections for an eye was 6.7 (range, 2-16 injections). The average VEGF and Ang2 levels at baseline were 30.5pg/ml and 34.3pg/ml; at the most recent injection, 4.5pg/ml (p<0.0001) and 21.5pg/ml (p<0.012), respectively. For controls (n=97), the mean VEGF level was 31.7pg/ml. Average CMT at baseline was 416µm and at last injection, 325µm (p<0.025). OCT data were available for 236 samples (40 eyes) and a significant correlation was found between VEGF levels and CMT (p<0.013)
Conclusions :
Aqueous levels of VEGF and Ang2 were significantly reduced after treatment with anti-VEGF agents. With the ease of obtaining the aqueous sample and measuring the VEGF and Ang2 levels, this may be a useful parameter, in addition to visual acuity and retinal thickness, to personalize the treatment of patients with eAMD.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.