Recent Trends in Retinal and Choroidal Imaging

Abstract

During the past decade ophthalmology has witnessed tremendous development in visualization techniques for the posterior segment of the eye. Fundus auto-fluorescence (FAF) is a relatively new, non-invasive imaging modality to evaluate RPE function. FAF uses the fluorescent properties of lipofuscin to provide a density map of lipofuscin, the predominant ocular fluorophore, in the retinal pigment epithelium. FAF is useful in the evaluation of a wide range of diseases involving the retina, RPE and choroid including degenerative, dystrophic, inflammatory, infectious, neoplastic, and toxic etiologies, it's also helpful to investigate patients with unknown visual loss or a positive family history of hereditary retinal diseases. According to the concentration of lipofuscin, lesions are categorized as hyper-auto fluorescent, hypo-auto fluorescent and iso-fluorescent. In patients with early dry AMD, alterations at the level of the RPE may become visible in areas that appear normal on fundus examination. fluorescent areas so FAF can be used as a prognostic tool as areas with increased FAF signal, which reflect excessive RPE lipofuscin build-up, precede the development of new areas or the enlargement of pre-existing atrophic patches in geographic atrophy. Retinal dystrophies show alternate hyper- autofluorescence and hypo- autofluorescence with their progression.