gms | German Medical Science

7th International Symposium on AMD: Age-related Macular Degeneration – Understanding Pathogenetic Mechanisms of Disease

20.09. - 21.09.2019, Baden-Baden

Analysis of the vascular properties of the choroidal neovascularization (CNV) undergoing fibrovascular transformation in neovascular AMD using optical coherence tomography angiography (OCTA)

Meeting Abstract

  • Marius Book - Münster/D
  • M. Ziegler - Münster/D
  • K. Rothaus - Münster/D
  • M.L. Farecki - Münster/D
  • G. Spital - Münster/D
  • A. Lommatzsch - Münster/D; Essen/D
  • D. Pauleikhoff - Münster/D; Essen/D

7th International Symposium on AMD: Age-related Macular Degeneration - Understanding Pathogenetic Mechanisms of Disease. Baden-Baden, 20.-21.09.2019. Düsseldorf: German Medical Science GMS Publishing House; 2020. Doc19amd40

doi: 10.3205/19amd40, urn:nbn:de:0183-19amd402

Veröffentlicht: 5. Februar 2020

© 2020 Book et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Purpose: The CNV in nAMD, despite Anti-VEGF therapy, transforms into a fibrovascular lesion. The variety in vasculature and their correlation with exudative changes are unknown. As most-established angiographic procedure, the fluorescein angiography allows only few Conclusions about structural changes within the CNV. The aim of this study was to describe the vascular properties of the CNV undergoing fibrovascular transformation using OCTA.

Methods: In this prospective, comparative, non-interventional study, 35 eyes with CNV undergoing fibrovascular transformation in nAMD and a history of at least 24 months of Anti-VEGF therapy were included. Spectral-domain coherence tomography (SD-OCT, Spectralis) and OCTA (OptoVue) were performed. The fibrovascular lesions were delineated in the en face SD-OCT images. For the analysis of the vasculature using OCTA we defined a slab by manually adjusting the segmentation levels to 60µm beneath Bruch’s membrane and the upper edge of the hyperreflective lesion. We applied the custom slab in ten eyes and superimposed the data with the respective SD-OCT images using MATLAB (MathWorks). In addition to the CNV itself, an adjacent rim (para-rim) and another one beyond (peri-rim) both with the width of 1mm, were investigated. Skeletonized OCTA images were analyzed for vascular parameters.

Results: The average CNV area of the cohort was 3.83±0.73mm², the average area of the para-rim was 3.74±1.06mm² and of the peri-rim 3.49±1.39mm². The mean vessel density within the fibrovascular lesion was 0.41±0.1%, within the adjacent rims 0.38±0.01%. The fibrovascular lesion had both a larger total vessel length (52.90±10.27mm) and a larger proportion of large-caliber vessels (5.9±2.6%) than the para-rim (47.38±14.50mm, 5.0±0.02%) and peri-rim (44.31±18.14mm, 5.0±0.02%). The mean degree of the node of the vessels was 1.42±0.02 in the CNV, higher than in the para-rim (1.35±0.03) and peri-rim (1.33±0.02). The mean length of the extracted line segments was 44.89±1.26µm in the fibrovascular lesion, 46.21±1.56µm in the para-rim and 47.23±1.34µm in the peri-rim. Other parameters showed no differences in the areas.

Conclusion: In this study the vascular properties of the CNV undergoing fibrovascular transformation have been described using OCTA. Differences between the fibrovascular lesion and the adjacent para- and peri-rim could be detected. In addition to a higher vascular density, the fibrovascular lesion also showed a higher degree of branched, short and large-caliber vessels than the adjacent rims. To what extent these descriptions of the fibrovascular lesion can help to identify different patterns of regression of the CNV must be analyzed in further studies.