High intravitreal TGF-β1 and MMP-9 levels in eyes with retinal vein occlusion

Purpose Vascular endothelial growth factor is a leading target to reduce macular oedema and improve visual acuity in patients with retinal vein occlusion (RVO), whereas the role of vascular destabilizing and fibroproliferative transforming growth factor (TGF)-beta 1 and matrix metalloproteinases (MMP)-2 and -9 in pathological manifestations of RVO is anticipated but less studied. Methods Undiluted vitreous samples were collected from three central RVO and one branch RVO eyes, all with neovascularization and fibrosis-related sight-threatening complications of RVO. Undiluted vitreous samples of 40 eyes operated due to non-ischemic condition either macular hole or pucker were used as controls. Growth factor and protease concentrations were measured by ELISA and gelatin zymography. Results Vitreous concentrations of TGF-beta 1 (92.0 +/- 17.4 pg/ml vs 18.3 +/- 27.0 pg/ml, mean +/- SD; P = 0.002) and MMP-9 (847.9 +/- 1196.4 AU/ml vs 87.7 +/- 174.0 AU/ml; P = 0.010) were higher in the eyes with ischemic RVO than in the controls. Conclusions High intravitreal levels of TGF-beta 1 and MMP-9 are found in RVO eyes having neovascular and fibrosis manifestation. Further studies are warranted to elucidate whether targeting TGF-beta 1 and MMP-9 could be beneficial in patients with ischemic RVO.