Abstract
Purpose: :
The introduction of spectral domain optical coherence tomography (SD-OCT) offers the potential to visualize the pathophysiologic conditions in a three-dimensional (3D) fashion, with higher resolution and less motion artifacts due to higher scanning speed. A study was performed to characterize and compare particular morphologic details between two SD-OCT systems in different retinal pathologies with presence of macular edema.
Methods: :
30 eyes of 30 patients with neovascular age-related macular degeneration (nAMD, n=10), branch retinal vein occlusion (BRVO, n=10) and central serous chorioretinitis (CSC, n=10) were included into this prospective trial. A standardized protocol was performed for comparative imaging of macular edema. The evaluation included Snellen visual acuity, Stratus OCT (Carl Zeiss Meditec, Inc.), 3D OCT-1000 (Topcon Corporation) and Cirrus HD-OCT (Carl Zeiss Meditec, Inc.) examination. For 3D imaging a FDA approved commercially available Software was used to control and eliminate motion artifacts. In a subsequent step, a second software was used to visualize datasets three dimensionally.
Results: :
In general, higher axial resolution of both SD-OCT systems enabled for better differentiation of pathophysiologically relevant details and retinal layers compared to radial scans of conventional Stratus OCT. By high-resolution raster OCT different types of intraretinal edema can be recognized: in BRVO large cysts were identified in the inner and outer nuclear layer, whereas cystoid changes in nAMD were located in the outer nuclear layer. Retinal thickness in CSC relates to subretinal fluid only in a specific dome shaped configuration.
Conclusions: :
SD-OCT systems have markedly improved retinal imaging capability by adding relevant information due to higher resolution and faster data acquisition. Higher scanning speed of the Cirrus HD-OCT reduced motion artifacts within the 3D dataset.3D imaging of macular edema shows specific pathophysiologic alterations in topographic detail and enables for a quick overview on large amounts of data. Characteristic patterns of edema distribution could be identified for different macular pathologies.
Keywords: retina • macula/fovea • imaging/image analysis: clinical