Abstract
In patients with hereditary retinal degenerations and age related macular degeneration (AMD) novel optical imaging techniques provide new opportunities for understanding the biological basis of visual loss and determining whether innovative forms of intervention are effective in preventing blindness. Advances in Adaptive Optics imaging, Optical Coherence Tomography and Molecular Imaging allow the investigation of photoreceptor distribution, thickness of the different retinal layers and the effects of specific molecular species associated with the pathologies. Autofluorescence (AF) imaging which targets lipofuscin in the Retinal Pigment Epithelial cell layer allows the study of its role in Stargardts disease and AMD. Newer methods currently being used in animal models are expected to soon be translated to patient investigations. These include direct visualisation of the fundamental biological process of apoptosis (programmed cell death) in the living eyes of rodent and primate models. The psychophysical measurement of rod and cone mediated visual function on a microscopic scale in the eyes of patients with localized regions of retinal dysfunction provides an understanding of the functional consequences of the abnormalities seen by the imaging studies. In some cases of AMD striking abnormalities in AF can co-exist with nearly normal cone function while rod function is severely compromised. These techniques allow investigation of the biological basis of visual loss, its natural history and the potential beneficial effects of novel treatments including gene therapy.