Abstract
Purpose :
To investigate the difference between 840 (SD-OCTA) and 1060 nm (SS-OCTA) optical coherence tomography angiography in visualizing CNV patterns, in age-related macular degeneration (nAMD).
Methods :
A total of 19 eyes from 19 subjects with nAMD were included. OCTA volume scans of the CNV lesion area were acquired by two different devices: First, using a custom built SS-OCTA (1060nm, 400.000 A-scans/s, 16°, 5mm x 5mm SPOCTA method) and second, using the AngioVue (OptoVue, CA) SD-OCTA (840nm, 70.000 A-scans/s, SSADA technology, 3x3 or 6x6 mm). For visualization of the neovascular complex in en face projection images, a horizontal detection plane and automated layer segmentation were used in 1060 and 840 nm OCTA, respectively. Two physicians independently graded CNV-patterns.
Results :
13 of 19 eyes were available for evaluation, excluding cases of strong motion artefacts.
840 nm OCTA revealed a vascular loop pattern in 23.1% (3), a dense net configuration in 30.8% (4) and no eyes with mixed pattern.
In 1060 nm OCTA 15.4% (2) had a vascular loop pattern, 38.5% (5) a dense net pattern and in 30.8% (2) a mixed pattern was observed.
5 eyes were graded differently in 840 and 1060 nm OCTA images. However, the inter-grader reliability coefficient was κ=1 for CNV patterns.
In 46.2% (6) of treatment-naive nAMD eyes no CNV associated pattern could be detected in 840 nm OCTA. 1060nm OCTA did not show a neovascular complex in two eyes (15.4%). This equals a test sensitivity of .54 for 840 and .85 for 1060 nm OCTA (n=13), respectively.
A detailed CNV classification revealed heterogeneous characteristics. However, 1060 nm OCTA was able to detect CNV patterns involving small details such as well defined CNV lesions (7/4), branching tiny capillaries (8/5) and anastomosis loops (7/5) more often than 840 nm OCTA.
Conclusions :
In conclusion we could show that 1060 nm OCTA was able to detect CNV associated vascular patterns more reliably than 840 nm OCTA. Also CNV characteristics involving small details are displayed better in 1060 nm OCTA.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.