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Updated: Jan 22, 2026
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Multimodal Volumetric Retinal Imaging by Oblique Scanning Laser Ophthalmoscopy oSLO and Optical Coherence Tomography OCT
Published on: August 4, 2018
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Signal Strength Reduction Effects in OCT Angiography.
Jeffrey J Yu1, Acner Camino1, Liang Liu1
1Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
Ophthalmology. Retina
|July 2, 2019
Summary
Optical Coherence Tomography Angiography (OCTA) vessel density (VD) measurements are significantly impacted by signal strength. Researchers should account for signal strength variations when interpreting OCTA data to ensure accuracy.
Area of Science:
- Ophthalmology
- Medical Imaging
- Biomedical Engineering
Background:
- Optical Coherence Tomography Angiography (OCTA) is a key imaging modality for visualizing retinal vasculature.
- Accurate quantification of vessel density (VD) is crucial for diagnosing and monitoring various eye conditions.
- The influence of signal strength on OCTA-derived VD measurements requires thorough investigation.
Purpose of the Study:
- To investigate the relationship between signal strength index (SSI) and vessel density (VD) in OCTA.
- To evaluate the impact of signal strength variations on VD measurements across different OCTA platforms.
Main Methods:
- A cross-sectional study involving healthy volunteers.
- OCTA images were acquired using Optovue/AngioVue and Cirrus/AngioPlex OCTA systems.
- Signal strength was systematically reduced using neutral density filters and defocus to assess its effect on VD.
Main Results:
- A statistically significant linear decrease in VD was observed as signal strength decreased on both OCTA systems.
- The magnitude of VD reduction varied based on the method of signal strength alteration (NDFs > defocus).
- Both signal strength index and participant age were significant factors influencing interindividual VD variation.
Conclusions:
- OCTA-based VD measurements are demonstrably affected by OCT signal strength.
- Caution is advised when interpreting VD data from OCTA scans due to potential signal strength bias.
- Development of OCTA quantification algorithms should aim to mitigate signal strength-related inaccuracies.
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