Differences in retinal neovascular tissue and vitreous humour in patients with type 1 and type 2 diabetes.

AIMS

The aim of the study was to evaluate the histopathology of neovascular tufts and vitreous samples collected from patients with diabetes.

METHODS

Vitreous samples and neovascular tufts were collected from patients with type 1 (n = 13) and (n = 17) type 2 diabetes with proliferative retinopathy, and from controls with a macular hole (n = 5). Neovessels were analysed using immunohistochemistry and vitreous samples with an enzyme-linked immunosorbent assay (ELISA). The main outcome measure was to examine differences in the levels of growth factors in patients with type 1 and type 2 diabetes with proliferative retinopathy.

RESULTS

Vascular endothelial growth factor (VEGF)-A was most strongly present in the samples from patients with type 1 diabetes. In type 2 diabetes, VEGF-D was more abundantly present than in type 1 diabetes. Angiopoietin (ANG)-2 was also abundantly present. Macrophages and nuclear factor kappa B (NFkappaB) were found, indicating the presence of an inflammatory process in the neovascular tissues.

CONCLUSIONS

VEGF-A and ANG-2 are equally important in the neovascular process in both type 1 and type 2 diabetes. VEGF-D is abundantly present in type 2 diabetes. In order to achieve better control of diabetic retinopathy, it might be beneficial to develop treatments that prevent the actions of ANG-2 and VEGF-D.