Single-shot, depth-encoded multiplexed OCT for multi-spot tracking of induced transient corneal dynamics

Area of Science:

• Biomedical Optics
• Medical Imaging
• Ophthalmology

Background:

• Assessing corneal biomechanics is crucial for diagnosing pathologies like keratoconus.
• Current methods often use global metrics or single-meridian scanning, missing focal stiffness changes.
• High temporal bandwidth and multi-point coverage are needed for transient mechanical events.

Purpose of the Study:

• To develop a simultaneous multi-spot air-puff optical coherence tomography (OCT) system.
• To overcome limitations of global metrics and single-meridian scanning for detecting focal corneal stiffness changes.
• To enable artifact-resistant measurement of rapid transient mechanical events.

Main Methods:

• Developed a simultaneous multi-spot air-puff OCT system using space-division multiplexing with depth encoding.
• Tracked dynamic surface deformation at nine locations simultaneously with 10 µs temporal resolution.
• Introduced the "Asymmetry Vector" to quantify biomechanical imbalances.

Main Results:

• The system achieved simultaneous multi-point tracking of dynamic corneal deformation.
• The "Asymmetry Vector" strongly correlated with the location of corneal pathology in phantoms and human subjects.
• A novel "dual-indentation" deformation profile was observed.

Conclusions:

• Simultaneous multi-spot OCT enables artifact-resistant biomechanical mapping of transient dynamics.
• The developed system can detect focal corneal stiffness changes and aid in diagnosing keratoconus.
• This approach offers a scalable route for high-speed, multi-point characterization in various applications.