Fig 1.
3 x 3-mm2 en face Optical Coherence Tomography Angiography (OCTA) images of the same eye with a true superficial collateral crossing the horizontal raphe.
Segmentation of the SCP (A and B) and full retinal slab (C) illustrate that the collateral is confined to the SCP. Horizontal (blue) dashed lines correspond to OCT B-scans with red flow overlay shown below each en face image. The circle (yellow) in the B-scans corresponds to the flow signal of the collateral vessel, confirming its location in the SCP. Green and red lines in B-scan images demonstrate segmentation boundaries for the SCP and full retina, respectively.
Fig 2.
Optical Coherence Tomography Angiography (OCTA) imaging of collaterals.
Top row (A-D) shows OCTA en face images of an eye with both superficial diving and true deep collaterals, and corresponding OCT B-scans with red flow overlay directly below. Segmentation of the SCP (A) and DCP (B and C) illustrate that the superficial diving collateral connects its parent vessels in the SCP by coursing through the DCP, whereas the true deep collateral is confined to the DCP. The full retinal thickness slab (D) shows the combined superficial diving collateral and its parent vessels in one segmentation. Bottom row (E-H) shows OCTA en face images of an eye with a foveal collateral, and corresponding OCT B-scans with red flow overlay directly below. Segmentation of the SCP (E) and DCP (F and G) illustrate two parent vessels connected at the fovea by the foveal collateral (H). Horizontal (blue) dashed lines correspond to OCT B-scans with red flow overlay shown below each en face image. The circle (yellow) in the B-scans correspond to the flow signal of the collateral vessel. Green lines in B-scan images demonstrate segmentation boundary between the SCP and DCP.
Table 1.
Number of collateral vessels for each study eye in 3 x 3-mm2 optical coherence tomography angiography scans.
Table 2.
Characteristics of 23 patients (n = 25 eyes) with retinal vein occlusion at the time of imaging with optical coherence tomography angiography.
Table 3.
Optical coherence tomography angiography findings in 3 x 3-mm2 scans (n = 25 eyes) in eyes with retinal vein occlusion.