The potential of nanomedicine therapies to treat neovascular disease in the retina

Abstract

Neovascular disease in the retina is the leading cause of blindness in all age groups. Thus, there is a great need to develop effective therapeutic agents to inhibit and prevent neovascularization in the retina. Over the past decade, anti-VEGF therapeutic agents have entered the clinic for the treatment of neovascular retinal disease, and these agents have been effective for slowing and preventing the progression of neovascularization. However, the therapeutic benefits of anti-VEGF therapy can be diminished by the need for prolonged treatment regimens of repeated intravitreal injections, which can lead to complications such as endophthalmitis, retinal tears, and retinal detachment. Recent advances in nanoparticle-based drug delivery systems offer the opportunity to improve bioactivity and prolong bioavailability of drugs in the retina to reduce the risks associated with treating neovascular disease. This article reviews recent advances in the development of nanoparticle-based drug delivery systems which could be utilized to improve the treatment of neovascular disease in the retina.

Figure 1

Schematic representation of the retina and sites of pathogenic neovascularization. (A) Illustration of the eye, with the anterior segment consisting primarily of the lens, iris, and cornea and the posterior segment consisting primarily of the vitreous and retina. The small box highlights the location of the retinal tissue which lines the back of the eye and is diagramed in more detail. The retina is stratified into highly ordered layers as labeled in the picture. (B) Retinal neovascularization occurs when retinal capillaries pass through the inner limiting membrane and invade the retinal tissue, primarily in the ganglion cell layer. (C) Choroidal neovascularization occurs when choroidal capillaries pass through Bruch's membrane and invade the RPE and subretinal space.