Aqueous humor concentrations of vascular endothelial growth factor and pigment epithelium-derived factor in high myopic patients.

Purpose: To compare the aqueous humor levels of vascular endothelial growth factor (VEGF) and pigment epitheliumderived factor (PEDF) in high myopic eyes and control eyes. Methods: Aqueous humor samples were collected from 21 highly myopic eyes of 20 patients (high myopia group) and from 30 cataract eyes of 30 patients with no choroidal neovascularization (CNV) or other ocular or systemic diseases (control group). Of the 21 high myopic eyes, 13 had no complications secondary to high myopia (high myopia with no complications group), 3 had posterior staphyloma (high myopia with staphyloma group), and 5 had chorioretinal atrophy (high myopia with chorioretinal atrophy group). The aqueous humor levels of VEGF and PEDF were determined by using commercially available enzyme-linked immunosorbent assay kits. Results: Aqueous humor levels of VEGF were significantly lower in the high myopia group compared to that in the control group (p<0.001). VEGF levels decreased with an increase in the axial length (p<0.001). PEDF levels tended to be higher in the high myopia group compared to that in the control group; however, the difference was not significant. Three high myopia groups had significantly lower VEGF/PEDF ratios than the control group (p=0.000, 0.002, and 0.005). Conclusions: Aqueous humor levels of VEGF in the high myopia group were significantly lower than those in the control group. The differing levels of VEGF and PEDF in the high myopia and control groups suggest that high myopia disrupts the VEGF/PEDF balance in retinal pigment epithelium (RPE) cells. High myopia is associated with degenerative changes such as thinning of the retinal pigment epithelium, chorioretinal atrophy, posterior staphyloma, lattice degeneration, and choroidal neovascularization (CNV) in the posterior segment of the eye [1-3]. Conversely, diabetic retinopathy is less severe in myopic patients, and myopic refraction and a longer axial length are associated with a lower risk of diabetic retinopathy, particularly vision-threatening retinopathy [4-6]. Vascular endothelial growth factor (VEGF) is an endothelial cell mitogen and a vasopermeability factor [7]. VEGF plays an essential role in ischemic retinal neovascularization and CNV secondary to age-related macular degeneration [8-12]. In contrast, pigment epitheliumderived factor (PEDF) acts as an anti-angiogenesis [13], an anti-inflammatory [14,15], or a neuroprotective factor [16]. There has been several studies about the role of VEDF and PEDF in development of CNV, and anti-VEGF therapy has been used for treating CNV. In the previous study [17,18], it has been reported that the VEGF concentration in the aqueous