Purpose To evaluate the morphological structure of ill-defined choroidal neovascularisation (CNV) with traditional fluorescein angiography (FA) compared with optical coherence tomographic angiography (OCTA).
Methods A retrospective case series study of 11 eyes with ill-defined CNV on FA was performed. Eyes were scanned with commercially available spectral-domain optical coherence tomography (OCT) (70 000 A-scans/s). The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to distinguish blood flow from static tissue. En face OCT angiograms were compared with FA.
Results Eleven cases of ill-defined CNV on FA were identified from 10 study participants. Mean age of the participants was 74.5±6.8 years. Six cases had late leakage from undetermined source (LLUS) and five had fibrovascular pigment epithelial detachment (FVPED). Combining cross-sectional structural OCT with OCT angiograms, all cases were found to have type 1 CNV that corresponded to occult CNV with FA. In all cases of occult CNV on FA, distinct vascular structures were visible with OCTA in the outer retinal/retinal pigment epithelium slab. The mean CNV vessel area was 2.61±3.65 mm2. The mean CNV vessel area in cases with FVPED was larger than that in cases with LLUS (4.69±4.72 mm2 compared with 0.85±0.90 mm2, Mann-Whitney p value=0.04).
Conclusions Although the sample size is small to draw conclusions and the nature of work is retrospective and descriptive, OCTA has the potential to improve visualisation of ill-defined CNV with dye-based angiography, including occult CNV.
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Contributors All authors made substantial contributions to the conception and design of the work, the acquisition, analysis and interpretation of data, drafting of the work and revising it critically for important intellectual content. All authors provided final approval of the version published and are in agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Funding (a) National Institute of Health grants: R01-EY024544, DP3-DK104397, R01-EY023285 and P30-EY010572. (b) Research to Prevent Blindness Unrestricted/Challenge (U/C) Grant.
Competing interests Oregon Health & Science University (OHSU), YJ and DH have a significant financial interest in Optovue, a company that may have a commercial interest in the results of this research and technology. DH has a significant financial interest in Carl Zeiss Meditec. These potential conflicts of interest have been reviewed and managed by OHSU. The other authors have no conflict of interest or relevant financial disclosure.
Ethics approval The Institutional Review Board at OHSU.
Provenance and peer review Not commissioned; externally peer reviewed.