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

Abstract

Purpose: To compare the aqueous humor levels of vascular endothelial growth factor (VEGF) and pigment epithelium-derived 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.

Figure 1

Aqueous humor VEGF levels. The 3 high myopia groups had lower VEGF concentrations compared to the control group (p<0.001, p=0.001, and p=0.007; Mann–Whitney test). The high myopia with posterior staphyloma group had the lowest VEGF levels.

Figure 2

Aqueous humor PEDF levels. The high myopia with no complications group and high myopia with posterior staphyloma group had higher PEDF levels compared to the control group and high myopia with no complications group (p=0.011 and 0.050, respectively; Mann–Whitney test).

Figure 3

VEGF/PEDF ratio in the control group and in high myopic patients. The 3 high myopia groups had a significantly lower VEGF/PEDF ratio than the control group (p=0.000, 0.005, and 0.002; Mann–Whitney test). In particular, high myopic patients with posterior staphyloma had a significantly lower VEGF/PEDF ratio than the high myopia with no complications group and high myopia with chorioretinal atrophy group (p=0.050 and 0.036, respectively; Mann–Whitney test).

Figure 4

Correlation between axial length and aqueous humor levels of VEGF and PEDF. VEGF concentrations depend on the axial length of the eyeball (p<0.001; r2=0.405; Pearson correlation test; A) while PEDF concentrations are not significant (p=0.169; Pearson correlation test; B).