Abstract
Purpose: :
Retinal angiogenesis in diabetic retinopathy is known to be a dynamic multistep prosess. Various growth factors and cytokines are known to be involved during retinal angiogenesis. The critical steps in this disease are known to be the angiogenic switch and the proteolytic processing of the extracellular matrix (ECM) environment. This study was performed to evaluate the profile of angiopoietin-1, angiopoietin-2, matrix metalloproteinase -2 and -9 and transforming growth factor-β in vitreous of diabetic patients with proliferative and non-proliferative diabetic retinopathy comparing data with controls operated due to nonvascular vitreoretinal diseases.
Methods: :
Prospective case-control study was performed in the unit of vitreoretinal surgery, Helsinki University Central Hospital in Finland during the years 2006-2008. Vitreous samples were collected before the start of the conventional three port pars plana vitrectomy (20G or 23G). Vitreous Ang-1, Ang-2, MMP-2, MMP-9 and TGF-β concentrations were measured from 247 human subjects: 69 patients with Type 1 or 2 diabetic retinopathy, and 178 control patients operated due to other vitreoretinal diseases (macular hole, epiretinal membrane, retinal detachment). Additionally, plasma samples of Ang-1 and Ang-2 were measured.
Results: :
Ang-2 concentrations were significantly higher in diabetic patients 1373 pg/ml compared to controls 309 pg/ml (p< 0.001). Respectively, TGF-β levels were elevated in diabetic patients compared to controls, 115 vs 28 pg/ml (p<0.001). Additionally, both MMP-2 and MMP-9 expression profiles were significantly higher in diabetic patients compared to controls (p=0.002 and p=0.003). There was a significant difference in plasma Ang-2 concentrations in diabetic patients compared to controls (p=0.009) but not in Ang-1 concentrations (p=0.925)
Conclusions: :
Our data confirm the previous findings that vitreous Ang-2, TGF-β and MMP-2 and MMP-9 seem to play a significant role in the pathogenesis of surgically treated patients with diabetic retinopathy.
Keywords: diabetic retinopathy • retinal neovascularization • vitreoretinal surgery