Abstract
Purpose: :
A recent study reported that patients with diabetic retinopathy had the lower incidence of age related macular degeneration. We experimentally studied the effect of diabetes on the development of choroidal neovascularization (CNV) induced by laser photocoagulation in mice.
Methods: :
Male wild-type mice (C57BL/6J) were studied and diabetes was induced with the intraperitoneal injection of streptozotocin (STZ). The animals were divided into 3 groups; the non-diabetic control group, the low dose STZ group which received 100 mg/kg of STZ and the high dose STZ group which received 200mg/kg of STZ. Two weeks after the STZ administration, the blood glucose levels (BGLs) were measured to confirm the induction of diabetes. Laser photocoagulation was used to induce CNV. The area of CNV was evaluated at 1 week after the laser photocoagulation. The levels of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) in the retina were determined by the enzyme-linked immunosorbent assay.
Results: :
The mean BGLs were 169.5 ± 78.3 mg/dl in the control group, 209.1 ± 70.6mg/dl in the low dose STZ group and 435.7± 227.0mg/dl in the high dose STZ group. The area of CNV was significantly greater in the diabetic animals than those in the control animals (mean ± SD; 2.86 ± 1.42 x 104 µm2 in the control, 5.57 ± 2.46 x 104 µm2in the low dose group and 5.79 ± 4.34 x 104 µm2 in the high dose group, P < 0.01). The mean ICAM-1 and VEGF levels were significantly increased in the retina of the diabetic mice as compared to the control mice.
Conclusions: :
These results suggested that diabetes facilitated the development of laser-induced CNV in mice and that the increase in the levels of VEGF and ICAM-1 in the diabetic retina may play a role.
Keywords: choroid: neovascularization • vascular endothelial growth factor • diabetes