Combined multiplanar optical coherence tomography and confocal scanning ophthalmoscopy

Abstract

We demonstrate the clinical application of a multiplanar imaging system that simultaneously acquires en face (C-scan) optical coherence tomography (OCT) and the corresponding confocal ophthalmoscopic images, along with cross-sectional (B-scan) OCT at specifiable locations on the confocal image. The advantages of the simultaneous OCT and confocal acquisition as well as the challenges of interpreting the C-scan OCT images are discussed. Variations in tissue inclination with respect to the coherence wave surface alter the sampling of structures within the depth of the retina, producing novel slice orientations that are often challenging to interpret. We have evaluated for the first time the utility of C-scan OCT for a variety of pathologies, including melanocytoma, diabetic retinopathy, choroidal neovascular membrane, and macular pucker. Several remarkable new aspects of clinical anatomy were revealed using this new technique. The versatility of selective capture of C-scan OCT images and B-scan OCT images at precise points on the confocal image affords the clinician a more complete and interactive tool for 3-D imaging of retinal pathology.

Clinical Application of Rapid Serial Fourier-Domain Optical Coherence Tomography for Macular Imaging

“…Recently, a report was published that showed the use of FD OCT to create volumetric representations of various macular lesions, which is an extension of the technique we have illustrated in this article. 16 Other reports have been published which demonstrate similar mapping techniques using time-domain OCT. 17,18,28 In those time-domain models, however, the map was created from a series of C-scans, a potential weakness of which is that most clinicians rely on B-scans for evaluation of the retina. Therefore, high-quality B-scans are more desirable than C-scans.…”

“…B-scans can be reconstructed from a direction different from the scanning direction, and C-scans (en face planes) can also be reconstructed from the same data. This reconstruction approach was first proposed and tested in clinical settings for en face time-domain OCT imaging, 17,18 in which retinal images were acquired in C-scans; however, to our knowledge, there have been no published reports applying this technique to FD OCT imaging in clinical settings.…”

Optical coherence tomography imaging in uveitis

“…In the Spectralis system, the retinal image (1,000 points) from the infra-red SLO imaging channel is used to track motion. In the RTVue system the motion is measured at 30 Hz from an infrared fullfield fundus camera [17,18]. The Cirrus system reduces eye motion artifacts with a proprietary scan acquisition strategy, a high-speed 20 Hz line scanning ophthalmoscope (LSO) camera, and single-pass alignment scanning.…”

“…En-face optical coherence tomography Podoleanu et al [24][25][26][27][28][29][30] developed a system combining confocal ophthalmoscopy and OCT, producing en-face OCT images that can be directly compared with transversal images provided by the confocal channel. In OCT, the depth resolution is determined by the bandwidth of the optical source used; therefore, en-face OCT and conventional longitudinal OCT achieve the same depth resolution as long as the source used is the same.…”

Visualization of vitreomacular tractions with en face optical coherence tomography

“…8,9 En face OCT combines OCT and confocal ophthalmoscopy, allowing to obtain longitudinal B-scans and coronal C-scans of the retina. [10][11][12] The confocal image, which has pixel to pixel correspondence with the coronal C-scan, allows a prompt visualization of the lateral extent of lesions on the posterior pole. Van Velthoven et al 10 have extensively explained how to interpret coronal scans of the neuroretina obtained with this new technique in various macular diseases.…”