scholarly journals Optical Coherence Tomography-Angiography of Different Choroidal Neovascularization Subtypes in Wet Age-related Macular Degeneration

Folia Medica ◽  
2019 ◽  
Vol 61 (2) ◽  
pp. 317-326
Author(s):  
Vladimir N. Stavrev ◽  
Nelly P. Sivkova ◽  
Desislava N. Koleva-Georgieva

Abstract Age-related macular degeneration is a leading cause of irreversible vision loss in individuals over 55 years of age worldwide. Conventionally, it is divided into two subtypes – dry (non-neovascular) and wet (neovascular) form. Neovascular age-related macular degeneration comprises only 10-15% of all patients but is responsible for more than 80% of blindness related to the disease. It requires early diagnosis and timely treatment. Fluorescein angiography is the current ‘gold standard’ for diagnosing neovascular forms. However, as an invasive procedure, it may be contraindicated in some circumstances and cause serious adverse effects. Optical coherence tomography-angiography is a relatively new, non-invasive and fast imaging modality gaining popularity in the diagnosis of age-related macular degeneration, especially for the neovascular form of the disease. It enables structural and functional information of blood vessels in the retina and choroid, without the need of an intravenous dye. In this study we present and discuss 3 cases of different subtypes of choroidal neovascularization secondary to neovascular age-related macular degeneration. All of them were examined by fluorescein angiography and optical coherence tomography-angiography. The results were qualitatively analyzed.

2021 ◽  
Vol 10 (4) ◽  
pp. 751 ◽  
Author(s):  
Jackson Scharf ◽  
Giulia Corradetti ◽  
Federico Corvi ◽  
SriniVas Sadda ◽  
David Sarraf

The advent of optical coherence tomography angiography (OCTA) has allowed for remarkable advancements in our understanding of the role of the choriocapillaris in age-related macular degeneration (AMD). As a relatively new imaging modality, techniques to analyze and quantify choriocapillaris images are still evolving. Quantification of the choriocapillaris requires careful consideration of many factors, including the type of OCTA device, segmentation of the choriocapillaris slab, image processing techniques, and thresholding method. OCTA imaging shows that the choriocapillaris is impaired in intermediate non-neovascular AMD, and the severity of impairment may predict the advancement of disease. In advanced atrophic AMD, the choriocapillaris is severely impaired underneath the area of geographic atrophy, and the level of impairment surrounding the lesion predicts the rate of atrophy enlargement. Macular neovascularization can be readily identified and classified using OCTA, but it is still unclear if neovascularization features with OCTA can predict the lesion’s level of activity. The choriocapillaris surrounding macular neovascularization is impaired while the more peripheral choriocapillaris is spared, implying that choriocapillaris disruption may drive neovascularization growth. With continued innovation in OCTA image acquisition and analysis methods, advancement in clinical applications and pathophysiologic discoveries in AMD are set to follow.


2020 ◽  
Vol 237 (11) ◽  
pp. 1312-1319 ◽  
Author(s):  
Marius Book ◽  
Martin Ziegler ◽  
Kai Rothaus ◽  
Henrik Faatz ◽  
Marie-Louise Gunnemann ◽  
...  

Abstract Purpose Choroidal neovascularization (CNV) in neovascular age-related macular degeneration (nAMD) undergoing anti-VEGF therapy transforms into a fibrotic lesion. This fibrovascular transformation is associated with a great variety of functional and morphological effects. The aim of this study was to investigate the vascular morphology of fibrotic CNV, to compare it with its surrounding tissue and to identify phenotypes using optical coherence tomography angiography (OCTA). Methods In 18 eyes with fibrotic CNV in nAMD spectral domain OCT (SD-OCT) and OCTA were performed. The automated segmentation lines were manually adjusted. A slab from 60 µm beneath Bruchʼs membrane to the inner edge of the subretinal hyperreflective material was applied. Quantitative analysis of the vascular morphology was performed using skeletonized OCTA images. Results Compared to the perilesional rim, the number of segments per area was significantly lower (234.75 ± 25.68 vs. 255.30 ± 20.34 1/mm2, p = 0.0003) within the fibrovascular lesion. Two phenotypes could be identified within the lesion. The phenotypic traits of cluster 1 were few, long and thick vascular segments; Cluster 2 was characterized by many, short and thin vascular segments (number of segments per area: 219.4 ± 18.8 vs. 258.8 ± 13.2 1/mm2, p = 0.00009, segment length: 49.6 ± 2.7 vs. 45.0 ± 1.3 µm, p = 0.0002, vascular caliber: 26.6 ± 1.2 vs. 23.5 ± 1.8 µm, p = 0.003). The clusters did not differ significantly regarding visual acuity (0.52 ± 0.44 vs. 0.54 ± 0.18 logMAR, p = 0.25), differentiability of subretinal (OR = 3.43, CI = [0.30, 39.64], p = 0.6) and intraretinal fluid (OR = 5.34, CI = [0.48, 89.85], p = 0.14). Less normalized ellipsoid zone (EZ) loss could be observed in cluster 1 (131.0 ± 161.3 vs. 892.4 ± 955.6 1/m, p = 0.006). Conclusion In this study the vascular morphology of fibrotic CNV was analyzed using OCTA. Differences between the lesion and a perilesional rim could be detected. Two phenotypes within the fibrovascular lesion were identified. These morphological clusters could indicate different patterns of fibrovascular transformation of the CNV under long-term anti-VEGF therapy and be useful identifying possible predictive biomarkers in future studies.


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