Multi-camera optical tracking and fringe pattern analysis for eye surface profilometry in ocular proton therapy.

Area of Science:

• Ophthalmology
• Medical Physics
• Biomedical Engineering

Background:

• Intraocular tumor treatment with proton therapy requires precise eye tracking.
• Current methods may lack the necessary accuracy for optimal radiation delivery.

Purpose of the Study:

• To design and validate an optical tracking system for high-precision eye position and orientation measurement.
• To enable accurate three-dimensional (3D) topography of the anterior eye segment during proton irradiation.

Main Methods:

• Developed a system using four optical cameras and two projectors.
• Employed Fourier Transform Method (FTM) with fringe pattern analysis for 3D topography.
• Integrated stereo triangulation and FTM for phase-to-physical coordinate mapping.
• Validated the system pre-clinically and on patients undergoing proton therapy, comparing results with MRI.

Main Results:

• Achieved sub-millimetric accuracy (median: 0.58 mm) and precision (RMSE: 0.61 mm) in pre-clinical tests.
• Demonstrated a median discrepancy of 0.43 mm (IQR: 0.65 mm) between MRI and FTM-based reconstructions.
• Confirmed the system's capability for reliable eye surface topography acquisition.

Conclusions:

• The developed optical tracking system meets precision and accuracy requirements for image-guided ocular proton therapy.
• The system is ready for clinical testing to evaluate its performance against current standards.
• This technology is expected to enhance the safety and efficacy of proton therapy for intraocular tumors.