Structural and functional imaging of the human and small animal eyes using ultrahigh speed Fourier domain optical coherence tomography

Abstract

Optical coherence tomography (OCT) is a non-invasive optical imaging technique that allows the three-dimensional structure of biological tissue to be visualized with micrometer resolution. In ophthalmology OCT has the unique advantage that it provides cross-sectional images of the retina and choroid noninvasively and in vivo, which have led OCT to be a clinical standard for the diagnosis of a variety of retinal diseases. Although current commercial Fourier domain OCT systems have high imaging speeds of 20-100kHz A-scan rates, these imaging speeds are not sufficient for more advanced structural and functional imaging techniques. Current state-of-the-art spectral domain and swept source OCT provide ultrahigh imaging speeds of >200kHz A-scan rates. These speeds enable functional imaging of retinal blood flow, OCT angiography of the retinal and choroidal microvasculature, and wide field volumetric structural imaging of the retina and choroid. In this thesis, advances in structural and functional ophthalmic imaging techniques for the human and small animal eyes are investigated using ultrahigh speed Fourier domain OCT. The following topics are discussed: (1) a method for numerically extracting and compensating dispersion mismatch in ultrahigh resolution spectral domain OCT, (2) ultrahigh speed spectral domain imaging in the small animal eye for measuring total retinal blood flow, (3) development of ultrahigh speed phase stable swept source OCT system for human retinal imaging, (4) OCT angiography of the choriocapillaris in the human eye, (5) clinical applications of OCT angiography in retinal diseases, including diabetic retinopathy and age-related macular degeneration, (6) small animal anesthesia protocol for functional hemodynamic imaging, and (7) imaging of neurovascular coupling in small animals using ultrahigh speed OCT.