Optical Coherence Tomography Angiography: Employing a Novel Technique for Investigation in Vogt-Koyanagi-Harada Disease

Abstract

Purpose: To report a case of Vogt-Koyanagi-Harada (VKH) disease and describe the imaging findings by means of optical coherence tomography angiography (OCTA). Methods: Medical and ophthalmological history, ophthalmological examination, laboratory evaluation, B-scan ultrasonography, fluorescein and indocyanine angiography, and optical coherence tomography (OCT) were performed at baseline, as well as OCTA. Results: A 50-year-old healthy female presented with decreased vision in both eyes. A Topcon DRI OCT Triton Plus swept source OCT system was used to visualize and evaluate the retinal and choroidal vascular plexus. Patchy and confluent dark areas in the superficial and deep retinal capillary plexus and choriocapillaris corresponded to areas of hypoperfusion, analyzed as areas of ischemia. Conclusions and Importance: VKH disease is characterized by ocular, neurological, and integumentary findings in its complete form. We present a case of incomplete disease in a 50-year-old female evaluated by means of OCTA which is a novel technique that provides depth-resolved images of the retina and choroidal microvasculature without dye injection that allows better visualization and detailed evaluation of the retinal and choroidal vascular plexus.

Role of optical coherence tomography angiography in Vogt-Koyanagi-Harada disease

“…Of note, these foci correlated with ICGA and decreased in number and size after initiation of therapy [ 15 ]. Similar OCTA findings in VKH have been reported by another case series [ 16 ] and two case reports [ 17 ], [ 18 ].…”

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).…”

Correlations Between Different Choriocapillaris Flow Deficit Parameters in Normal Eyes Using Swept Source OCT Angiography

“…4,9,10 In addition, CC flow impairments evaluated using OCTA has been reported in eyes with diseases such as age-related macular degeneration (AMD), diabetic retinopathy, central serous chorioretinopathy, retinitis pigmentosa, idiopathic epiretinal membrane, Vogt-Koyanagi-Harada disease, and Alport syndrome. 5,[11][12][13][14][15][16][17][18][19] However, the extent of CC flow impairments reported from different studies have been difficult to compare because different instruments and algorithms have been used to generate and analyze the CC en face flow images and because the capillaries of the CC are beyond the resolution of commercial OCTA instruments so investigators lack the ground truth evidence that they are truly imaging the CC in vivo based on OCTA images. 8-12, 14-17, 20-25 Different terms have been used to evaluate CC flow and flow impairments such as CC vessel flow density (VFD), vessel density (VD), vessel diameter index (VDI), perfusion density (PD), vessel length density (VLD), flow voids (FVs), grey value (GV), signal voids, percent choriocapillaris area of nonperfusion (PCAN), 8,9,[20][21][22][23][24][25][26] but we prefer to use the term flow deficits (FDs), since these areas represent regions of undetectable CC flow when using a particular instrument and algorithm rather than the absolute absence of physiological CC flow, since flow might be detectable under different circumstances.…”