Dispersion compensation for spectral domain optical coherence tomography by time-frequency analysis and iterative optimization

Abstract

We report a new numeric dispersion compensation method for the device’s dispersion mismatch in a spectral-domain optical coherence tomography (SD-OCT) for imaging the iridocorneal angle of human cadaver eyes. The dispersion compensation term is calculated by an automated iterative process that minimizes the wavenumber-dependent variance of the ridge extracted from the spatial-spectral distribution of a mirror’s spectral interferogram using short-time Fourier transform (STFT). Our method can extract different amounts of dispersion robustly, and the algorithm can work in a wide range of combinations of window sizes and overlaps when using an STFT. Comparable point spread functions (PSFs) are shown to a traditional polynomial fitting method. Lastly, we verified that our imaging system is able to visualize the iridocorneal angle details, such as trabecular meshwork (TM), Schlemm’s canal (SC), and collector channels (CCs), which are important ocular outflow structures associated with glaucoma management.