Eye movement |
Thin horizontal or vertical white lines
leading to loss of integrity of the vessels on the en-face angiogram in
conjunction with interruption, displacement, doubling or ghosting of
vessels, and/or quilting defect. This type of artifact can result in
duplication or removal of some parts of retinal vessels from the scan.
This artifact was classified as severe if it affected more than 10% of
the total B-scans comprising the en-face angiogram. |
Defocus |
Decrease in reflective intensity and clear
visualization of the details of small vessels on the angiogram. Mostly
results from decreased reflectance intensity scores in the entire
B-scans comprising the angiogram. This artifact was classified as severe
if it affected more than 10% of the total B-scans comprising the en-face
angiogram. |
Shadow |
Decreased intensity of retinal layers in
isolated areas, often owing to vitreous floaters or corneal opacities.
As a result, these structures cannot be clearly visualized and are
replaced with dark areas in the en-face angiogram. This artifact was
classified as severe if it affected more than 10% of the total B-scans
comprising the en-face angiogram. |
Decentration |
Translocation of the center of the optic nerve
head (ONH) or macula from the center of the en-face angiogram to the
periphery of the scan. The OCTA algorithm may or may not be able to
correctly identify the new center of the ONH or macula. This artifact
was classified as severe if it resulted in loss of more than 10% in any
adjacent retinal sectors of the ONH or macula. |
Segmentation error |
Erroneous identification of the borders of
superficial vascular layer by the automated segmentation algorithm
resulting in a deviation of more than 50% of the total thickness
diameter in a B-scan. This artifact was classified as severe if it was
observed in more than 10% of total B-scans comprising the en-face
angiogram. |
Blink |
Total loss of reflectance intensity in an area
of adjacent B-scans because of a blink during the scan capture. It
results in horizontal or vertical black lines on the en-face angiogram.
This artifact was classified as severe if it affected more than 5% of
the total B-scans comprising the en-face angiogram. |
Z offset |
Loss of the peripheral borders of B-scans
(obtained in both horizontal and vertical raster pattern) due to
malalignment of head position during scan capture. This type of artifact
happens if the display of a B-scan falls out of the operator window for
scan acquisition while capturing the scan. This artifact was classified
as severe if it affected more than 5% of the total B-scans comprising
the en-face angiogram. |