Purpose: To describe a novel imaging technique, which we call "dense B-scan optical coherence tomography angiography" (DB OCTA), in which thin dense raster scans are used to produce highly resolved structural B-scans with superimposed flow signal that provide precise correlation between retinal microstructure and blood flow.
Design: Observational case series.
Methods: Normal eyes and eyes with macular findings of interest were imaged with DB OCTA in which 150-400 OCT B-scans were acquired within a narrow area (from a single line to 1 degree) with a width of 10-30 degrees. B-scans containing 5-7 consecutive frames were processed for OCTA signal and then combined and visualized post-acquisition by application of a Gaussian filter across neighboring scans. The result was a single, smoothed, high-resolution image that contained both structural and flow information. Tracked follow-up DB OCTA was used to detect subtle changes in pathology over time.
Results: Two hundred and thirty-seven eyes from 205 subjects aged 18-100 years (mean 72.88 ± 14.74 years) with a diverse range of macular findings were imaged with DB OCTA. Highly resolved scans showing precise localization of flow signal were readily obtained, even in patients with poor visual acuity and/or poor fixation. We present clinical examples that demonstrate the utility of DB OCTA for visualizing the associations between retinal microstructure and blood flow.
Conclusions: DB OCTA enables precise correlation between retinal microstructure and blood flow. The ability to obtain accurately aligned follow-up DB OCTA studies has the potential to refine the understanding and clinical management of a wide range of macular diseases.
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