Optical Coherence Tomography Angiography of the Eye by Huang David;Lumbroso Bruno; & Bruno Lumbroso & Yali Jia & Nadia K. Waheed

Author:Huang, David;Lumbroso, Bruno; & Bruno Lumbroso & Yali Jia & Nadia K. Waheed [HUANG, DAVID]
Language: eng
Format: epub
ISBN: 4931465
Publisher: SLACK, Incorporated

17

Polypoidal Choroidal Vasculopathy

Min Wang, MD, PhD; Simon S. Gao, PhD; and Yali Jia, PhD

Polypoidal choroidal vasculopathy (PCV) features a variety of clinical manifestations, such as quiescent orange subretinal nodules (polyps), serous and/or hemorrhagic detachments of the retinal pigment epithelium (RPE), serous subretinal fluid that mimics central serous chorioretinopathy, and massive submacular hemorrhage.1-3 PCV has a higher prevalence in Asian, Black, and pigmented races.4 Indocyanine green angiography (ICGA) has been an essential tool for differentiating PCV from neovascular age-related macular degeneration.5,6 ICGA findings include nodular hyper-fluorescence corresponding to orange sub-retinal nodules, hypo-fluorescent halo around the nodules, and a branching vascular network (BVN) that terminates in pulsating polyps.7,8 Spectral domain optical coherence tomography (OCT) shows typical structural changes such as a dome-shaped pigment epithelium detachment (PED) with a hyper-reflective signal underneath the RPE and separation of the RPE and Bruch’s membrane (also referred to as the double-layered sign) corresponding to the abnormal BVN. En face OCT reveals the BVN as a hyper-reflective area around or beside the dome-shaped PED.

Although OCT provides information on abnormal structures in PCV, it does not provide blood flow information. In the last 2 years, optical coherence tomography angiography (OCTA), a new imaging technique that allows the acquisition of blood flow information in the vessels of the retina and choroid, has been made practical by the development of the split-spectrum amplitude-decorrelation algorithm developed by Jia and Huang.9,10 This revolutionary imaging technique allows us to acquire blood flow information on PCV in a noninvasive, fast, and efficient way.

The OCTA images in this chapter were captured with the Avanti RTVue-XR spectral domain OCT system using AngioVue software (Optovue Inc, Fremont, CA). ICGA was performed with the Spectralis HRA + OCT (Heidelberg Engineering). Automated segmentation software was used to identify anatomic reference planes, with manual correction by a human grader when necessary. En face angiograms were produced by maximum flow projections in anatomic slabs. The inner retinal slab was defined as the layer lying between the inner limiting membrane and the inner plexiform layer, inclusively. The outer retinal slab was defined as the layer lying between the outer plexiform layer and Bruch’s membrane, inclusively. Manual correction was made for any error in the output of the automated segmentation. Custom adjustment of the slab depth was made to best show the pathology, and these depth settings are indicated in the figure captions. To create composite en face angiograms of the inner retina and neovascular membrane, the inner retinal angiogram (purple) was overlaid on the outer retinal angiogram (yellow) that contained the choroidal neovascularization. Composite cross-sectional B-scan images were created in a similar fashion by overlaying flow (pseudocolor) on structural OCT (grayscale) images.

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