Authors: Sung Pyo Park, Jae Kyoun Ahn, South Korea

Advantages / Purpose:

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 ten healthy controls and forty patients with BRVO. Aqueous levels of VEGF and PEDF were measured by ELISA at the time of IVB and six weeks later. Non-response to IVB was defined as showing persistent macular oedema based on the reduction of central macular thickness (CMT) by less than 20 percent from baseline measurements by optical coherence tomography and vision improvement by < 0.3 logMAR at 6 weeks after IVB. Fluorescein angiography (FA) was performed after resolution of foveal hemorrhage. We compared aqueous levels of VEGF and PEDF between responders and non-responders.

Effectiveness / Safety:

The aqueous levels of VEGF and PEDF were significantly higher in 16 nonresponders than in 24 responders at baseline measurements (491 ± 231 pg/ml vs. 250 ± 112 pg/ml, P < .001; 32 ± 4 ng/ml vs. 25 ± 5 ng/ml, P <. 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 <. 001; 30 ± 8 ng/ml vs. 18 ± 5 ng/ml, P < .001, respectively). FA revealed that non-responders showed higher frequencies of macular ischemia and ischemic BRVO.

Take home message:

Our results indicate that aqueous VEGF levels are associated with persistent macular oedema secondary to ischemic BRVO following IVB.