*4.1.1 Patient-related motion artifacts*

One common cause of image artifacts is from eye movements caused by breathing, palpitations, or tremors (**Figure 7**). In general, eye movement artifacts appear as thin horizontal or vertical white lines (7A). They may cause duplication or removal of the retinal vessels shown in the image leading to an overall loss of vessel integrity. Blink

**Figure 7.** *Examples of patient related motion artifacts.*

*The Role of Optical Coherence Tomography Angiography in Glaucoma DOI: http://dx.doi.org/10.5772/intechopen.110272*

**Figure 8.** *Examples of operator or motion related OCTA artifacts.*

artifacts occur when a patient blinks during scan capture which causes loss of reflectance intensity in an area of adjacent B-scans (7B). The displacement of multiple Bscans can cause horizontal or vertical black lines on the *en-face* angiogram. Refraction error, also described as banding, is caused by a temporary change in corneal refractive power when the patient-device distance fluctuates during acquisition (7 C). Crisscross is an eye movement artifact that appears as a rectangular pattern when the software fails to correct multiple saccades (7D).
