Vascular Endothelial Growth Factor, Basic Fibroblast Growth Factor, and Pigment Epithelium-Derived Factor Expression in the Neovascular Iris in Retinal Diseases.

Heng Miao,Xianru Hou,De-Kuang Hwang,Yong Tao

doi:10.1155/2018/8025951

Abstract

Objective To determine the expression of cytokines in the iris of patients with neovascular glaucoma (NVG). Methods Patients with NVG associated with proliferative diabetic retinopathy (PDR, group 1) or central retinal vein occlusion (CRVO, group 2) who had undergone surgical treatment were enrolled. Patients with primary open-angle glaucoma requiring surgical treatment were included in the control group (group 3). All iris specimens were obtained during trabeculectomy, 7 days after intravitreal injections of ranibizumab. The messenger RNA (mRNA) and protein levels of three target cytokines—vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and pigment epithelium-derived factor (PEDF)—in the iris were analyzed and compared. Results We included 39 eyes from 39 patients (12, 15, and 12 in groups 1, 2, and 3, resp.). The protein and mRNA levels of PEDF were higher in two NVG groups. The protein levels, but not mRNA level, of bFGF were higher in the two NVG groups. The protein and mRNA levels of VEGF were similar in the three groups. Conclusions The protein level of bFGF increased in the irises of the NVG patients was not expressed by the iris itself, whereas PEDF may be expressed by the iris tissue in these patients.

Highlights

intraocular pressure elevation are mainly caused by the mechanical blockage of the aqueous outflow
inflammatory cytokines participate in the formation of iris neovascularization
the pathogenesis of iris neovascularization may be ascribed to the anterior diffusion of cytokines

Summary

Introduction

Neovascular glaucoma (NVG) is a type of glaucoma in which progressive optic nerve damage and intraocular pressure elevation are mainly caused by the mechanical blockage of the aqueous outflow of neovascularization from the iris and anterior chamber angle [1]. NVG [1, 5, 6] In these patients, the pathogenesis of iris neovascularization may be ascribed to the anterior diffusion of cytokines that are expressed by hypoxic retinal tissues; standard treatment options focus on the blockage of cytokines and the treatment of the ischemic retina, such as retinal photocoagulation and cryotherapy [3]. After chronic intraocular inflammation and ischemia, the iris tissue may itself secrete various factors and cytokines to compensate for the imbalance

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Results

Conclusion