Advances in the diagnosis, management and pathophysiology of capillary nonperfusion

Abstract

‘Capillary dropout’ or ‘nonperfusion’ describes both an anatomic condition and an angiographic appearance in many retinal diseases. In this review, we will discuss several illustrative pediatric and adult retinal vascular diseases including retinopathy of prematurity, familial exudative vitreoretinopathy, diabetic retinopathy and retinal vein occlusions with capillary nonperfusion. Enhanced retinal imaging techniques have demonstrated that capillary nonperfusion is more common in vascular diseases than previously assumed. A large body of experimental evidence in animal models has started to elucidate the underlying pathophysiology of this process. In addition, it has become clear in hereditary and congenital diseases that genetic mutations involving Wnt signaling are integral to retinal vascular development and disease. Defects in the Wnt signaling pathway seem to be related to abnormalities in retinal vascular formation and/or angiomaintenance. Abnormalities in either of these processes may lead to capillary nonperfusion. We review clinical features of capillary nonperfusion and discuss the evolving management of this entity based on novel imaging modalities and molecular mediators.