Impact of enhanced resolution, speed and penetration on three-dimensional retinal optical coherence tomography

Abstract

: Recent substantial developments in light source and detector technology have initiated a paradigm shift in retinal optical coherence tomography (OCT) performance. Broad bandwidth light sources in the 800 nm and 1060 nm wavelength region enable axial OCT resolutions of 2-3 mum and 5-7 mum, respectively. Novel high speed silicon based CMOS cameras at 800 nm and InGaAs based CCD cameras in combination with frequency domain OCT technology enable data acquisition speeds of up to 47,000 A-scans/s at 1060 nm and up to 312,500 A-scans/s at 800 nm. Combining ultrahigh axial resolution, ultrahigh speed OCT at 800 nm with pancorrected adaptive optics allows volumetric in vivo cellular resolution retinal imaging. Commercially available three-dimensional (3D) retinal OCT at 800 nm (20,000 A-scans/s, 6 mum axial resolution) is compared to ultrahigh speed 3D retinal imaging at 800 nm (160,000 A-scans/s, 2-3 mum axial resolution), high speed 3D choroidal imaging at 1060 nm (47,000 Ascan/ second, 6-7 mum axial resolution) and cellular resolution retinal imaging at 800 nm using adaptive optics OCT at 160,000 A-scans/second with isotropic resolution of ~2 mum. Analysis of the performance of these four imaging modalities applied in normal and pathologic eyes focusing on motion artifact free volumetric retinal imaging and revealing novel, complementary morphological information due to enhanced resolution, speed and penetration is presented.

Three-dimensional motion correction using speckle and phase for in vivo computed optical interferometric tomography

“…It is known that these computed imaging techniques are more sensitive to motion along the slow axis [15] and also that motion is more difficult to correct along the slow axis due to missing information [1,2]. Therefore, the amplitude of motion along the slow axis was kept smaller (~9.4 µm) while the fast-axis motion was kept the same (~14.7 µm).…”

“…Motion in tissues has always been problematic for in vivo imaging in high-resolution optical systems [1][2][3]. From retinal to cardiac movements, these involuntary motions make it difficult to acquire and process artifact-free in vivo data.…”

High-speed OCT light sources and systems [Invited]

“…This may limit imaging speed for some medical and biological applications which have a limited permitted sample exposure, see e.g. the discussions in [9,119]. However, it can be shown that even for sensitive application.…”

“…Image-degrading motion artifacts are inevitable for many samples such as the human retina [119]. Complex hardware and numerical correction schemes have been employed [166], but they are difficult to implement and need to be tailored to the specific application.…”

Artefact reduction for cell migration visualization using spectral domain optical coherence tomography

“…SD-OCT in the 800 nm region currently outperforms SS-OCT in terms of resolution due to the availability of broadband lasers. Also SD-OCT now achieves ultra high-speed, comparable to the fastest available SS-OCT systems due to advances in camera technology [16][17][18]. However, SD-OCT requires a significant amount of signal processing for background handling and resampling.…”