Structural and functional human retinal imaging with a fiber-based visible light OCT ophthalmoscope

Area of Science:

• Biomedical Optics
• Ophthalmology
• Medical Imaging

Background:

• Optical Coherence Tomography (OCT) is crucial for non-invasive retinal imaging.
• Existing OCT systems face limitations in resolution, speed, and functional imaging capabilities.
• Fiber-based systems offer potential for miniaturization and enhanced performance.

Purpose of the Study:

• To design and characterize a multi-functional fiber-based OCT system for high-resolution human retinal imaging.
• To evaluate the performance of different supercontinuum light sources for OCT applications.
• To demonstrate the system's capability for structural and spectroscopic retinal imaging.

Main Methods:

• Development of a fiber-based OCT system utilizing a broadband fiber coupler for visible wavelengths.
• Noise characterization of two supercontinuum light sources with varying pulse repetition rates.
• Integration of the sample arm into an ophthalmoscope platform for in vivo imaging.
• Acquisition of retinal images at different exposure levels and axial scan rates.

Main Results:

• Achieved < 2 micron axial resolution in tissue.
• Identified a higher repetition rate, lower noise light source enabling 96 dB sensitivity with 0.15 mW power.
• Demonstrated in vivo retinal imaging at speeds up to 70,000 axial scans per second.
• Successfully performed in vivo spectroscopic imaging of retinal anatomy, saturation, and hemoglobin content.

Conclusions:

• The developed fiber-based OCT system provides high-resolution, high-speed, and multi-functional imaging of the human retina.
• The system's performance is suitable for clinical applications and advanced research.
• The demonstrated spectroscopic capabilities open avenues for quantitative physiological assessment of the retina.