Comparison of Time–Domain (OCT–3) and Fourier–Domain Optical Coherence Tomography in Imaging Macular Diseases

Abstract

Abstract: : Purpose: To compare retinal images acquired with time–domain optical coherence tomography (OCT) (Zeiss OCT–3) and high–speed and high–resolution Fourier–domain OCT for a variety of macular diseases. Methods: OCT images were acquired from 50 patients with different macular diseases using a commericial OCT system ( Carl Zeiss Meditec, OCT–3) and a Fourier–domain OCT system built at the UC Davis Medical Center (superluminescent diode centered at 840 nm, optical bandwidth: 50 nm, scan rate: 10,000 A–scans/s, axial resolution: 6 µm). Cross–sectional 2D images were obtained with both OCT systems; 3D images were obtained with Fourier–domain –OCT only. Images were compared to determine if Fourier–domain OCT provides better visualization and localization of disease processes. Results: Images obtained with the Fourier–domain OCT provided enhanced visualization of individual retinal layers and better localization of disease processes. Retinal and vascular structures in exudative age–related macular degeneration, which were not visible in the standard OCT, could be identified with the Fourier–domain OCT due to better image penetration depth, increased contrast and decreased motion artifacts. Conclusions: Fourier–domain OCT imaging allows enhanced visualization of macular diseases, permitting more accurate localization and morphologic characterization of pathology. This may prove useful in monitoring disease progression and evaluating treatment efficacy.

Keywords: retina • imaging/image analysis: clinical • macula/fovea