Pigment epithelium-derived factor and vascular endothelial growth factor in branch retinal vein occlusion with macular edema

We investigated whether pigment epithelium-derived factor (PEDF) or vascular endothelial growth factor (VEGF) influence macular edema in patients with branch retinal vein occlusion (BRVO). This investigation aimed to clarify the influence of PEDF in the vitreous fluid on retinal vascular permeability in patients with macular edema secondary to BRVO. The findings were expected to be useful for the treatment of macular edema in BRVO patients. This was a retrospective cross-sectional comparative case series. Thirty-three BRVO patients with macular edema and 24 control patients with nonischemic ocular diseases were enrolled. Retinal ischemia was evaluated by measuring the area of capillary nonperfusion on fluorescein angiography with Scion Image software. Macular edema was examined by optical coherence tomography. Vitreous fluid samples were obtained via pars plana vitrectomy, and the VEGF and PEDF levels were determined by enzyme-linked immunosorbent assay. The vitreous level of VEGF was significantly higher in BRVO patients than controls (P < 0.001). The vitreous PEDF level was significantly lower in BRVO patients than controls (P = 0.026). In BRVO patients, vitreous levels of PEDF and VEGF showed a significant negative correlation with each other (P < 0.001). Additionally, the vitreous VEGF level had a significant positive correlation (P < 0.001) and the vitreous PEDF level had a significant negative correlation (P < 0.001) with the nonperfused retinal area in BRVO patients. Furthermore, vitreous levels of VEGF and PEDF showed significant positive (P = 0.001) and negative (P = 0.014) correlations, respectively, with macular edema in BRVO patients. VEGF and PEDF may inversely influence retinal vascular permeability in patients with ischemic BRVO and macular edema. However, prospective validation will be needed to confirm these observations.