Changes of aqueous vascular endothelial growth factor and pigment epithelium‐derived factor following intravitreal bevacizumab for macular oedema secondary to branch retinal vein occlusion

A bstract Background: To investigate sequential changes of aqueous vascular endothelial growth factor (VEGF) and pigment epithelium‐derived factor (PEDF) in macular oedema secondary to branch retinal vein occlusion (BRVO) following intravitreal injection of bevacizumab (IVB). Methods: We recruited 10 healthy controls and 40 patients with BRVO. Aqueous levels of VEGF and PEDF were measured by ELISA at the time of IVB and 6 weeks later. Non‐response to IVB was defined as showing persistent macular oedema based on reduction of central macular thickness by less than 20% from baseline measurements by optical coherence tomography and vision improvement by <0.3 logMAR at 6 weeks after IVB. Fluorescein angiography was performed after resolution of foveal haemorrhage. We compared aqueous levels of VEGF and PEDF between responders and non‐responders. Results: The aqueous levels of VEGF and PEDF were significantly higher in 16 non‐responders than in 24 responders at baseline measurements (491 ± 231 pg/mL vs . 250 ± 112 pg/mL, P < 0.001; 32 ± 4 ng/mL vs . 25 ± 5 ng/mL, P < 0.001, respectively). Six weeks after IVB, the aqueous levels of VEGF and PEDF were still higher in non‐responders than in responders (388 ± 141 pg/mL vs . 104 ± 40 pg/mL, P < 0.001; 30 ± 8 ng/mL vs . 18 ± 5 ng/mL, P < 0.001, respectively). Fluorescein angiography revealed that non‐responders showed higher frequencies of macular ischaemia and ischaemic BRVO. Conclusions: Our results indicate that aqueous VEGF levels are associated with persistent macular oedema secondary to ischaemic BRVO following IVB.