Introduction:

Proliferative diabetic retinopathy (PDR) is characterized by pathologic retinal neovascularization. It can arise from the optic disc (NVD), retina (NVE) and/or the iris (NVI).

Clinical Features:

Retinal neovascularization is a hallmark of PDR, which can be seen at the slit lamp as fine networks of blood vessels extending from the retina into the vitreous cavity (Fig. 13.3.1). These vessels can cause visual loss secondary to vitreous hemorrhage, and can induce preretinal fibrosis leading to tractional retinal detachment, retinoschisis, macular edema and combined traction/rhegmatogenous RD

Neovascularization may occur at the disc or elsewhere (NVE) in the retina. It may be preceded by intraretinal microvascular abnormalities (IRMA), which represent a severe form of NPDR.