Abstract
Abstract: :
Purpose: Imaging of retinal structures using scanning laser ophthalmoscopes can provide additional information compared to funduscopy or fundus photography. For example, autofluorescence imaging identifies lipofuscin deposition and pathologic changes within the retinal pigment epithelium, infrared imaging (IR) reveals drusen and pigmentary changes with high sensitivity. In cases of classic choroidal neovascularisation, photodynamic therapy (PDT) with visudyne has been established as a new treatment approach primarily in patients with age-related macular degeneration. In this study we analysed infrared images before and after treatment with visudyne and compared the images to fluorescein- and ICG-angiograms and clinical appearance. Methods: Patients with classic choroidal neovascularisation (CNV) which were eligible for photodynamic therapy with visudyne were recruited for the study. Infrared imaging at 795 nm as well as fluorescein and indocyanine green angiograms were gained with a HRA scanning laser ophthalmoscope (Heidelberg Engineering) in standard settings. Images were taken before PDT and 8 weeks after treatment, for up to 12 months. Results:Twenty patients with classic choroidal neovascularisation could be included in the study, nineteen had age-related macular degeneration, one patient had retinopathia serpingiosa. Thirteen patients showed increased IR-reflectancy in the area of neovascularisation, in contrast to seven patients with little IR-reflectancy. Interestingly, the eyes with little IR-reflectancy increased in IR-reflectancy after PDT treatment. Funduscopy and Fluorescein angiography revealed that increased IR-reflectancy correlates with beginning or active fibrotic process involving retinal pigment epithelium (RPE) cells of the CNV and that PDT seems to induce this process. In CNV with initially increased IR-reflectancy seem already to be in this process and also showed clinically progressed disease. In the time course, the IR-reflectancy became weaker as the fibrosis completed. Conclusions: IR-imaging could be an additional non-invasive diagnostic tool for identifying the response potential of CNV membranes to PDT in conversion to fibrovascular tissue.
Keywords: imaging/image analysis: clinical • photodynamic therapy • clinical (human) or epidemiologic studies: sys