Choroidal Granulomas Visualized by Swept-Source Optical Coherence Tomography Angiography

Abstract

Purpose: To assess the visualization of choroidal granulomas with swept-source optical coherence tomography angiography (OCTA). Methods: Consecutive patients with granulomatous choroiditis due to tuberculosis, sarcoidosis, or Vogt–Koyanagi–Harada disease underwent baseline OCTA images using a 12 × 12-mm field of view, and the choroidal slabs were analyzed by two independent examiners who counted the oval areas of flow void. Simultaneously, indocyanine green angiography (ICGA) and enhanced-depth imaging OCT were performed to mark visible choroidal changes corresponding to granulomatous lesions. The lesion areas on OCTA and ICGA were assessed using the in-built caliper tool. Results: Three hundred and one round-shaped areas of flow void on OCTA, 209 hypofluorescent round lesions on ICGA, and 42 hyporeflective choroidal lesions on enhanced-depth imaging OCT were identified in 23 eyes from 14 patients. Of the 209 ICGA granulomas, 197 (94.3%) had a corresponding round area of flow void on OCTA that was interpreted as a granuloma. One hundred and four additional round flow voids were identified on OCTA that did not correspond to any hypofluorescent lesion on ICGA. The mean area of the 197 granulomas detected with both imaging modalities was significantly larger on ICGA (mean 0.33 mm2) than that on OCTA (mean 0.28 mm2). Conclusion: Optical coherence tomography angiography seems to be an optimal imaging method for the visualization of choroidal granulomas.

Microvasculature Features of Vogt-Koyanagi-Harada Disease Revealed by Widefield Swept-Source Optical Coherence Tomography Angiography

“…Therefore, SS-OCTA is a better imaging modality tool for detailed chorioretinal angiography than SD-OCTA. Flow voids appear as dark foci in the OCTA CC slab and multiple studies have demonstrated that most FV revealed by OCTA correspond to hypofluorescent spots on ICGA images (19,24,(39)(40)(41)(42) and hyporeflective spots on enhanced-depth imaging (EDI)-OCT (43). Aggarwal et al reported that the CC FV on OCTA images reflected true CC ischemia instead of a shadowing effect from overlying subretinal fluid and RPE detachment as was observed in central serous chorioretinopathy (19).…”

“…Aggarwal et al reported that the CC FV on OCTA images reflected true CC ischemia instead of a shadowing effect from overlying subretinal fluid and RPE detachment as was observed in central serous chorioretinopathy ( 19 ). Thus, hypoperfusion spots in CC may be attributed to choroidal granulomas ( 24 , 39 ) or blood flow perturbance caused by choroidal vessel inflammation ( 39 ).…”

Uveitis as an Open Window to Systemic Inflammatory Diseases

“…OCT-Angiography of the posterior pole at the level of the choriocapillaris revealed areas of low flow co-located with hypofluorescent ICG spots, corresponding to choroidal granulomas. It has been shown recently that OCT-Angiography has a 94% sensitivity for the detection of posterior pole choroidal granulomas [ 140 ].…”

Imaging in Tubercular Choroiditis: Current Concepts

“…OCTA has been recently employed to study the pathological alterations of the choroid due to tuberculomas by Pichi et al 90 In their study, the authors included 23 eyes with choroidal granulomas (of which 8 eyes were affected by tuberculomas). Imaging was performed on a swept-source platform.…”

“…This impairs the choroidal blood flow and appears as areas of flow void on OCTA. 90,91 Aksoy et al have shown that not only these stromal granulomas cause choriocapillaris compression leading to flow voids, but also cause decreased vascular density in deep capillary plexus and increase in foveal avascular zone in the retina. 92 Thus, OCTA is very useful in detecting choriocapillaris and deeper choroidal changes in eyes with tuberculomas.…”