New Developments in Optical Coherence Tomography Technology

Abstract

Optical coherence tomography (OCT) represents the fasted adopted retinal imaging modality in the history of ophthalmology. Three-dimensional (3D) retinal OCT at 1,060 nm (as opposed to 800 nm) enables wide-field 3D visualization of the entire choroid, fairly irrespective of the patient’s fundus pigmentation. 3D OCT at 1,060 nm (as opposed to 800 nm) promises improved clinical feasibility for retinal imaging in patients with opaque ocular media in the anterior eye segment (e.g., cataract or corneal haze). Combining adaptive optics and OCT technology might pave the way for in vivo cellular resolution retinal imaging for routine diagnosis in the eye clinic. Extensions of OCT are recently developed that enable noninvasive depth resolved functional imaging of the retina, providing blood flow or physiologic tissue information. These extensions of OCT should not only improve image contrast, but should also enable the differentiation of retinal pathologies via localized metabolic properties or functional state. Polarization sensitive (PS)-OCT provides intrinsic, tissue-specific contrast of birefringent and depolarizing tissue. PS-OCT can be used to identify and segment the retinal pigment epithelium (RPE) based on its depolarizing property, and to analyze the retinal nerve fiber layer (RNFL) based on its birefringence Doppler OCT (D-OCT) provides quantitative information about retinal perfusion, in addition to standard OCT structure tomograms. D-OCT promises to improve early diagnosis by detecting microcirculation abnormalities as precursors of retinal diseases, and in general, vascular diseases.