Suspended scattering particles in motion using OCT angiography in branch retinal vein occlusion disease cases with cystoid macular edema

Abstract

We aimed to investigate the clinical implication of suspended scattering particles in motion (SSpiM) using optical coherence tomography angiography (octA) among branch retinal vein occlusion disease (BRVo) cases with macular edema (Me). Medical records of BRVo patients were reviewed. central retinal thickness (cRt), Me type, and cyst size on optical coherence tomography images were evaluated before and after intravitreal bevacizumab injection. nonperfusion area, SSpiM, and microvascular abnormalities in octA images were evaluated using a Heidelberg machine. SSpiM was identified in 24 of 56 cases. There were no differences in baseline characteristics between groups with and without SSpiM. Disease duration, disease-free duration, previous injection number, microaneurysms in the superficial vascular complex, and microaneurysms in the deep vascular complex (DVC) (p = 0.003, 0.013, 0.028, 0.003, < 0.001, respectively) differed significantly between the two groups. After multivariate logistic analysis, microaneurysms in the DVC were the only different factor between the two groups (odds ratio [OR]: 0.091; p = 0.001). Furthermore, SSPiM in the DVC (OR 10.908; p = 0.002) and nonperfusion grade (OR 0.039; p < 0.001) were significantly associated with cyst response after intravitreal injection. SSpiM may be correlated with microaneurysms in the DVc and a poor anatomical response after intravitreal injection. Branch retinal vein occlusion (BRVO) is a major vasculopathy among retinal diseases, and when it occurs, macular edema (ME) is also usually present and well-developed 1,2. Optical coherence tomography (OCT) and fluorescein angiography are widely used to assess various ocular diseases 3-5. However, OCT angiography (OCTA), which is a more recent technology, has greatly helped to elucidate differences in structural anomalies and identify anatomical vascular patterns not previously seen before 6-12. OCTA images are acquired by analyzing differences in reflectivity from repeated OCT B-scan images 13,14. Microvascular abnormalities such as microaneurysms, telangiectasia, and neovascularization can be assessed in OCTA images in addition to areas of nonperfusion as well as areas of vascular density. In most cases, distinction between areas of nonperfusion and vascular density is possible, but nonvascular decorrelation signals or artifacts may prevent such a distinction 15-17. In one study of nonvascular decorrelation signals, Kashani et al. proposed the concept of suspended scattering particles in motion (SSPiM) 18. They suggested that severe breakdown of the blood-retinal barrier (BRB) induces an increase in particle efflux and that SSPiM appear due to a decorrelation signal caused by Brownian motion of particles in intraretinal cysts. They also demonstrated experimentally that an intralipid solution generated SSPiM-like signals 18. In a previous study, we focused on and evaluated decorrelation signals like SSPiM in diabetic ME (DME) patients using OCTA images, and found that both steroid and anti-vascular endothelial growth ...

Evaluation of bioclinical markers to predict short term response to intravitreal anti-VEGF in treatment-naive diabetic macular edema and the “Fried Egg” sign : a novel OCT feature

“…(23,24) To the best of our knowledge this is the rst prospective study reporting the incidence of SSPiM in DME. (10,13,25) HRD were counted with a semi-automated software with low inter observer variability thus avoiding errors from manual counting. All the other studies used manual counting over a single line scan passing through the fovea.…”

Morphologic and Anatomical Features of Type 1 Macular Neovascularization Trunks in Age-Related Macular Degeneration Using Optical Coherence Tomography Angiography

“…Tram tracklike and donut ring-shaped MNV trunks may have incomplete vessel walls, and the surrounding leaking materials show decorrelation signals. Suspended scattering particles in motion, as a representative nonvascular decorrelation signal, [21][22][23] may appear near an incomplete vessel. The blood-retinal barrier could have a decorrelation signal on OCTA.…”