Abstract
Purpose: :
To build a CNV animal model closer to human and explore a new way anti-CNV for the prevention and treatment.
Methods: :
We chose 8 ordinary healthy adult rhesus monkeys. Each eye was performed 8 burns around the macular in a circular fashion with laser. The parameters of laser were as follow: spot size=50µm; laser power=0.4W; and exposure time=0.1 second. 20 days after laser photocoagulation, we used color fundus photography, fluorescein angiography and optical coherence tomography to detect and measure the evidence and extent of leakage of CNV. We randomly assigned them into a control group(NS) and three treatment groups: low-dose(100µg), sino-dose (300µg) and high-dose (500µg). Then we performed intravitreal injection of different doses of humanized anti-VEGF fusion protein. 2 and 4 weeks after the intravitreal administration, color fundus photography, fluorescein angiography, optical coherence tomography were performed to detect if any bleeding in fundus, the size of CNV and the change of CNV leakage. In the end, we took the eye balls and, after embedding, slicing and HE staining, observed the macular changes.
Results: :
20 days after laser, fibrous tissue proliferation became visible in color fundus photographs; FFA showed fluorescein leakage at early stage, formed high fluorescein mass at late stage. Optical coherence tomography findings also showed a typical performance of high-densiy red-and-white stripes, while few showed shallow retinal detachment. 2 weeks after intravitreal injection of humanized anti-VEGF fusion protein, no significant change occurred in low-dose group (P>0.05), while sino-dose and high-dose group both reduced the fluorescein leakage of choroidal neovascularization, whose effects were not significantly different (P<0.05). After 4 weeks, all treatment groups, especially the high-dose group, displayed reduction in the leakage caused by choroidal neovascularization, compared to the control group.
Conclusions: :
We successfully constructed the experimental choroidal neovascularization model by 532 nm laser within high power. Intravitreal injection of humanized anti-VEGF fusion protein can effectively inhibit the development of choroidal neovascularization.
Keywords: choroid: neovascularization • growth factors/growth factor receptors • protein purification and characterization