Multimodal Volumetric Retinal Imaging by Oblique Scanning Laser Ophthalmoscopy (oSLO) and Optical Coherence Tomography (OCT)
August 4th, 2018
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Here, we present a protocol to get a large field of view (FOV) three-dimensional (3D) fluorescence and OCT retinal image by using a novel imaging multimodal platform. We will introduce the system setup, the method of alignment, and the operational protocols. In vivo imaging will be demonstrated, and representative results will be provided.
Overview
This article presents a novel imaging multimodal platform for obtaining large field of view, three-dimensional fluorescence and OCT retinal images. The protocol includes system setup, alignment methods, and operational protocols, with in vivo imaging demonstrations and representative results.
Key Study Components
Area of Science
- Ophthalmology
- Retinal Imaging
- Fluorescence and OCT Imaging Techniques
Background
- The technique allows for imaging and quantification of blood-retina barrier disruption.
- It assesses retinal capillary functions.
- High-contrast images of retinal microvasculature can be obtained.
- It has implications for diagnosing diabetic retinopathy and other pre-retinal diseases.
Purpose of Study
- To demonstrate a method for large field of view retinal imaging.
- To provide insights into retinal imaging techniques.
- To explore applications in other imaging systems using conventional objective lenses.
Methods Used
- Oblique scanning laser for multi-contrast imaging.
- Single raster scan for three-dimensional imaging.
- In vivo imaging demonstrations.
- System setup and alignment protocols.
Main Results
- Successful acquisition of large field of view retinal images.
- Demonstrated capability to visualize single capillaries in 3D.
- Provided representative results showcasing the technique's effectiveness.
- Highlighted the method's advantages over traditional imaging techniques.
Conclusions
- The novel imaging platform enhances retinal imaging capabilities.
- It offers significant advantages for diagnosing retinal diseases.
- The technique can be adapted for use with other imaging systems.
Frequently Asked Questions
What is the main advantage of this imaging technique?
The main advantage is obtaining a large field of view, three-dimensional, multi-contrast retinal imaging in a single raster scan.
How does this method contribute to ophthalmology?
It helps in imaging and quantifying blood-retina barrier disruption and assessing retinal capillary functions.
Can this technique be used for other imaging systems?
Yes, it can be applied to other imaging systems using conventional objective lenses.
What diseases can this technique help diagnose?
It has implications for diagnosing diabetic retinopathy and other pre-retinal diseases.
What type of images can be obtained with this method?
High-contrast images of retinal microvasculature, down to single capillaries in 3D.
Is in vivo imaging demonstrated in this study?
Yes, in vivo imaging is demonstrated along with representative results.
Executive Industry Relevance
This multimodal imaging approach addresses a critical gap in ophthalmic research by enabling volumetric fluorescence and structural retinal imaging in a single scan, supporting mechanistic studies of vascular dysfunction and blood-retina barrier integrity. The ability to visualize retinal microvasculature in 3D with high contrast enhances target validation for neurodegenerative and metabolic disease models where retinal pathology serves as a biomarker. By combining oSLO with OCT, the platform provides complementary functional and anatomical data, improving predictive confidence in preclinical efficacy assessments.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of therapeutic hypotheses related to vascular leakage and capillary dropout in disease models.
- Operational Value: Provides quantitative 3D fluorescence readouts to assess target engagement and pathway modulation.
- Predictive Value: Supports biological de-risking by linking structural changes to functional vascular outcomes.
Screening & Assay Development
- Scientific Value: Generates standardized, multi-contrast volumetric datasets for reproducible compound screening.
- Operational Value: Facilitates assay readiness through single-raster-scan acquisition, reducing variability and increasing throughput.
- Scalability: Compatible with conventional objective lenses, enabling adaptation across imaging platforms.
Translational & Preclinical Research
- Translational Continuity: Bridges discovery and preclinical validation by providing disease-relevant imaging of retinal microvasculature.
- Biomarker Alignment: Supports evaluation of vascular biomarkers relevant to diabetic retinopathy and neurodegenerative conditions.
- Risk-Adjusted Advancement: Enables longitudinal monitoring of treatment effects on barrier function and perfusion.
Pipeline & Workflow Integration
The method integrates into discovery workflows by providing early-phase vascular phenotype data that informs lead identification and preclinical progression decisions.
- Discovery Biology: Supports hypothesis testing of vascular dysfunction mechanisms through direct visualization of capillary networks.
- Screening: Delivers quantitative, high-contrast fluorescence outputs suitable for automated image analysis and hit validation.
- Analytics: Enables 3D volumetric measurements and cross-sectional comparisons to quantify structural and functional changes.
- Translational Research: Connects to preclinical continuity via imaging of retinal layers implicated in human disease.
- Enterprise Reuse: Represents a reusable imaging capability for multi-modal retinal assessment across therapeutic areas.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence by reducing mechanistic ambiguity in vascular and neurodegenerative disease models.
- Operational Value: Enhances reproducibility and standardization through aligned optical paths and synchronized data acquisition.
- Strategic Value: Improves go/no-go decisions by providing early, multi-parametric retinal safety and efficacy signals.
- Portfolio Impact: Enables risk-adjusted prioritization of candidates based on retinal vascular integrity and functional readouts.
Implementation Considerations
- Requires expertise in optical system alignment, laser safety, and fluorescent dye handling.
- Needs stable imaging platform with galvanometer scanners, dichroic optics, and single-mode fiber coupling.
- Demands cross-team standardization for consistent anesthesia, dye dosing, and image acquisition protocols.
- Involves adaptation considerations when translating from rat to other model systems or tissue types.
- Involves practical limitations including photobleaching risk and motion artifacts if imaging exceeds two minutes without rest.
Biopharma FAQs
Why is volumetric fluorescence imaging important for target validation?
Volumetric fluorescence imaging enables direct visualization and quantification of vascular leakage and capillary dynamics in 3D, providing mechanistic insight into blood-retina barrier function. This supports target validation by linking molecular interventions to functional vascular outcomes in disease models. The technique avoids the need for z-stacking, improving throughput and reducing motion artifacts in longitudinal studies.
How does oblique scanning enable 3D imaging without sectioning?
Oblique scanning illuminates the retina at an angle, allowing the detection system to capture cross-sectional fluorescence images along the beam path, effectively creating tomographic slices in a single raster scan. This approach eliminates the need for physical sectioning or computational reconstruction from stacked images. The method leverages the inherent depth sensitivity of oblique illumination to generate volumetric data efficiently.
What quantitative measurements does volumetric fluorescein angiography enable?
Volumetric fluorescein angiography enables measurement of fluorescence intensity, vessel density, leakage extent, and capillary perfusion across retinal layers in 3D. These metrics support quantification of blood-retina barrier integrity and microvascular function in preclinical models. The technique provides contrast-enhanced visualization down to single capillaries, facilitating detailed morphological and functional analysis.
Why do replication requirements matter for cross-functional collaboration?
Replication ensures that vascular phenotypes and imaging results are consistent across operators, sites, and experimental batches, which is essential for reliable data sharing between discovery, preclinical, and translational teams. Standardized acquisition protocols and synchronized OCT-oSLO imaging reduce variability and increase confidence in comparative studies. This consistency supports regulatory-aligned biomarker qualification and multi-site preclinical validation efforts.
What statistical analysis capabilities are required before implementing this imaging method?
Implementation requires capability for 3D image registration, intensity normalization, and quantitative comparison of vascular parameters across conditions and time points. Statistical tools must support voxel-wise analysis, region-of-interest quantification, and longitudinal modeling of fluorescence changes. These capabilities enable objective assessment of treatment effects on vascular structure and function, supporting go/no-go decisions in drug development pipelines.
