Intravitreal injection of antiangiogenic agents is widely used to treat retinal vascular disease. This therapy can induce regression of neovascular vessels; reduce intraocular inflammation and retinal vascular permeability, and control macular edema. However the action period of these agents is short, and thus this therapy need repeated injections which cause higher operation risk and cost. Retinal laser photocoagulation therapy can close retinal capillary non-perfusion area and neovascular vessels, reduce macular edema caused by vascular leakage. However, as its therapeutic effect is based on the destruction of the retinal tissues in the lesion area, this therapy need longer time to show its effects. When the disease is controlled by this method, it may already induce some structural irreversible damages to the retina, especially the macular. This is why the visual acuity is not satisfactory in some patients, even though the disease get controlled, macular edema gets disappeared and anatomical structure of retina get improved. Properly evaluating all the pros and cons of retinal photocoagulation and intravitreal injection of antiangiogenic agents, will allow us to explore a better way to combine these two therapies to treat retinal vascular diseases.
Objective To investigate the effects and mechanism of curcumin on the retinal neovasularization in mice with oxygeninduced retinopathy (OIR). Methods A total of 72 C57BL/6J mice were divided into normal, OIR model, vehicle control ［dimethyl sulphoxide (DMSO)］, and curcumin group (100, 50, and 10 mg). The mice in normal group lived in normoxia condition; OIR model was set up according to standard methods in the literature. Five days after OIR establishment, the mice in curcumin group received an intraperitoneal (IP) injection of 0.1 ml curcumin (100, 50, and 10 mg), and the mice in DMSO group received an IP injection of 0.1 ml 1permil; DMSO. All of the mice were executed at the age of postnatal day 17 (P17) and the eyeballs were collected. Endothelial cell nuclei breaking through the internal limiting membrane were counted after stained with hematoxylin and eosin (HE). The expression of vascular endothelial growth factor-A (VEGF-A), vascular endothelial growth factor receptor-2 (VEGFR-2), endostatin (ES), and phosphorylated p38 mitogen-activated protein kinase (p-p38MAPK) in the retina in each group were measured by real-time polymerase chain reaction (RT-PCR) and Western blot methods.Results Compared with the normal group, retinal neovascularization was found in OIR model group (P＜0.05). The number of endothelial cell nuclei was 46.00plusmn;16.00 in OIR model group and 0.17plusmn;0.41 in normal group (P＜0.05). The expression of VEGF-A, ES, and p-p38MAPK in 100 mg curcumin group differed statistically from which in 50 and 10 mg curcumin group (P＜0.05). The expression of VEGFR-2 was same in the three curcumin groups (P＞0.05). Conclusion Curcumin can inhibit the formation of retinal neovascularization; the mechanism may be associated with inhibiting the expression of VEGFA and VEGFR-2, increasing the expression of ES, and inhibiting the p38MAPK signal transduction pathway.
Up-regulation of vascular endothelial growth factor (VEGF) is demonstrated to be a key role in formation process of intraocular neovascularization. Anti-VEGF treatment is the breakthrough of intraocular neovascular diseases therapy. Intrav itreal injection of antineovascularization drug looks to be an effective method on ocular neovascular diseases which with the advantages of good biocompatibility, low prices and longer intravitreal half-time etc. However, at present, it lack of multi-center study; the long-term efficacy and the systematic safety needs the further clinical verification. Various types of CNV showed the different therapeutic reactions to either PDT or Anti-VEGF agent, the treatment methods for exudative AMD include laser, PDT, and drug like Triamcinolone Acetonide，several anti-VEGF preparations. Therefore, understanding the pathogenesis of neovascular AMD and choosing a reasonable therapeutic methods are necessary. We should try to explore a safe, effective, economic, new approach. （Chin J Ocul Fundus Dis，2008，24：157-159）