060 SLO et OCT à haute résolution en imagerie simultanée dans la DMLA

Abstract

Purpose To image alterations associated with various phenotypes of age-related macular degeneration (AMD) by simultaneous confocal scanning laser ophthalmoscopy (cSLO) and high-resolution, spectral-domain optical coherence tomography (OCT). Methods OCT-images and simultaneous recording of fluorescein angiography, indocyanine green (ICG) angiography, infrared, redfree, or fundus autofluorecence (FAF) images were obtained with a novel imaging device (Spectralis HRA+OCT, Heidelberg Engineering, Heidelberg, Germany). An optically pumped solid state laser generates the excitation wavelength (488 nm) required for redfree, FAF and fluorescein angiography images. For ICG angiography and infrared imaging diode laser sources at 790 and 815 nm are used. For OCT 40.000 A-scans are acquired per second with 7 μm depth and 14 μm lateral optical resolution. The B-scans with an angle of 30 degrees have a scan width up to 1.536 A-scans with a digital lateral resolution of 6 μm/pixel, a scan depth of 500 pixels with 4 μm/pixel resolution and a scan rate up to 50 B-scans/sec. An integrated eye tracking allows for live averaging of cSLO-images as well as OCT B- scans. Results Early, atrophic and neovascular manifestations of age-related macular degeneration were examined and cSLO and OCT frames correlated. Fluorescein and ICG-angiographic phenomena recorded in cSLO images could be analysed in corresponding OCT-cross sections. Abnormal FAF-signals were correlated to alterations at the outer retinal/retinal pigment epithelial cell layer in high resolution OCT-scans. Three-dimensional OCT enabled comprehensive retinal coverage. The imaging software accurately tracked eye movements and allowed for precise monitoring at identical retinal sites at different time points following anti-VEGF-therapy. This facilitated evaluation of the drug-repsonse and indication for retreatments. Conclusion The combined cSLO/OCT system allows for simultaneous recordings of topographic and tomographic images. Particularly the pixel-to-pixel correlation between the confocal angiograms, FAF images and other imaging modes with the OCT scans may contribute to our understanding of the pathogenesis, and improve diagnosis and management of patients with AMD.