Human ciliary epithelium as a source of synthesis and secretion of vascular endothelial growth factor in neovascular glaucoma

Abstract

Importance: Retinal ischemia-induced upregulation of vascular endothelial growth factor (VEGF) leads to endothelial proliferation of the anterior segment, resulting in neovascular glaucoma.

Objective: To investigate the ciliary epithelium as a possible source of VEGF in human eyes enucleated for intractable neovascular glaucoma.

Design, setting, and participants: In this proof-of-concept, laboratory-based study, 16 human enucleated eyes (8 with neovascular glaucoma and 8 as controls) were investigated.

Main outcomes and measures: Presence of VEGF by immunohistochemical analysis (VEGF protein) and in situ hybridization (VEGF messenger RNA).

Results: In eyes with neovascular glaucoma, strong VEGF immunoreaction in the nonpigmented epithelial cells of the ciliary processes and in the retina was noted. In situ hybridization for VEGF messenger RNA revealed a similar pattern, with positive stain results only in eyes with neovascular glaucoma. A minimal amount of VEGF immunostaining was seen in control eyes.

Conclusions and relevance: The nonpigmented ciliary epithelium is an important site of VEGF synthesis in patients with neovascular glaucoma. The ciliary epithelium may represent an additional focus of treatment in the management of neovascular glaucoma, especially in eyes that are nonresponsive to panretinal photocoagulation.