Quantity and quality of image artifacts in optical coherence tomography angiography

Abstract

ObjectiveTo analyze quality and frequency of OCTA artifacts and to evaluate their impact on the interpretability of OCTA images.Design75 patients with diabetic retinopathy (DR), retinal artery occlusion (RAO), retinal vein occlusion (RVO), or neovascular age-related macular degeneration (nAMD) and healthy controls were enrolled in this cross-sectional study in the outpatient department of a tertiary eye care center.MethodsAll participants underwent an OCTA examination (spectral domain OCT Cirrus 5000 equipped with the AngioPlex module). OCTA scans were analyzed independently by two experienced ophthalmologists. Frequency of various artifacts for the entire OCTA scan and for different segmentation layers and the grading of OCTA interpretability were investigated.ResultsThe analysis of 75 eyes of 38 women and 37 men between 24 and 94 years were included. Six eyes had no retinal disease, 19 eyes had nAMD, 16 had DR, 19 eyes had RVO, and 15 eyes showed RAO. A macular edema (ME) was present in 40 of the diseased eyes. Projection artifacts occurred in all eyes in any structure below the superficial retinal vessel layer, segmentation and motion artifacts were found in 55% (41/75) and 49% (37/75) of eyes, respectively. Other artifacts occurred less frequently. Segmentation artifacts were significantly more frequent in diseased than in healthy eyes (p<0.01). Qualitative assessment of OCTA images was graded as excellent in 65% and sufficient in 25% of cases, adding up to 91% images deemed acceptable for examination. Presence of ME was associated with a significantly poorer interpretability (p<0.01).Conclusion and RelevanceVarious artifacts appear at different frequencies in OCTA images. Nevertheless, a qualitative assessment of the OCTA images is almost always possible. Good knowledge of possible artifacts and critical analysis of the complete OCTA dataset are essential for correct clinical interpretation and determining a precise clinical diagnosis.

Reliability of foveal avascular zone measurements in eyes with retinal vein occlusion using optical coherence tomography angiography

“…Also, evaluation of en face retinal maps could avoid projection artifacts misinterpretation. However, a pronounced edema or highly reflective intraretinal structures could produce masking artifacts in underlying layers [ 20 ]. Previous reports noticed the absence of capillaries detection in the areas of retinal cysts [ 21 , 22 ].…”

Peripapillary microvascular changes in patients with systemic hypertension: An optical coherence tomography angiography study

“…Finally, we only analyzed SCP, not DCP and choriocapillaries. However, previous studies have shown that projection artifacts may affect quantitative analysis of DCP and choriocapillaries, and Enders et al 34 reported that 75% of deep retina images were shown projection artifacts. Further studies on the changes of DCP and choriocapillaries using projection-resolved OCTA will be needed.…”

Retinal microvasculature alterations in myopic anisometropia on optical coherence tomography angiography

“…Further longitudinal studies may help to address the question of whether retinal vessel density is altered with age. Second, even subtle ocular movements during imaging can cause significant artifacts that may confound the analysis of the results; appropriate interpretation is needed to acquire a high-quality retinal vascular network image [26].…”