Neovascular Age-Related Macular Degeneration

Abstract

Age-related macular degeneration (AMD) progresses through early and intermediate to advanced stages, one of which is neovascular AMD (nAMD). A correct diagnosis of nAMD at an early stage is critical because unlike geographic atrophy, it can be treated with therapeutic agents. Diagnosis is made easier by a variety of imaging modalities that complement clinical examination. Microperimetry in conjunction with best-corrected visual acuity testing allows changes in morphology to be correlated with visual function in a single examination, while morphology itself can be monitored with multimodal imaging devices in addition to fundoscopy. Today’s gold standard two-dimensional fluorescein angiography, which evaluates both leakage and morphology, makes it possible to detect a choroidal neovascular lesion in its formative stage. Other two-dimensional en face examinations such as color fundus photography, fundus autofluorescence, red free imaging, and near-infrared imaging, including indocyanine green angiography both in normal and wide-field mode, each adds specific details about morphologic alterations. Three-dimensional spectral domain optical coherence tomography allows a precise and near-histologic evaluation of the retina in its entire depth extending from the internal limiting membrane to the retinal pigment epithelium. Depending on the morphology and device settings, it can even visualize structures below the retinal pigment epithelium like the choroid. A fourth dimension can be added by measuring, for example, the change in polarization state of the reflected light. All these imaging techniques and the detailed information for diagnosing nAMD that clinicians can gain from each of them are covered in the following chapter.