High resolution optical coherence elastography of retina under prosthetic electrode

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Physics

Background:

• Investigating the biomechanics of the retina is crucial for developing effective retinal prosthetics.
• Understanding the impact of implanted devices on retinal tissue is essential for patient safety and trial success.

Purpose of the Study:

• To quantitatively assess the biomechanical effects of a retinal prosthetic electrode on retinal layers.
• To gather data supporting the safety and efficacy of retinal prosthetic devices in potential clinical trials.

Main Methods:

• Utilized a high-resolution optical coherence tomography (OCT) based elastography (OCE) system to measure biomechanical properties.
• Assessed elastic wave propagation and axial displacement in rabbit retinas before and after prosthetic electrode implantation.
• Acquired anatomical B-mode images alongside elastography measurements.

Main Results:

• Spatial-temporal maps revealed elastic wave speeds in different retinal layers.
• Without the electrode, speeds ranged from 3.66 m/s (nerve fiber to inner plexiform) to 9.69 m/s (choroid to sclera).
• With the electrode, speeds slightly increased, with values like 4.09 m/s (nerve fiber to inner plexiform) and 9.99 m/s (choroid to sclera).

Conclusions:

• Retinal prosthetic electrodes cause only minor alterations in retinal elastic wave speed.
• The study demonstrates that these electrodes do not significantly affect the overall biomechanical properties of the retina.
• OCE technology holds promise for routine clinical evaluation of retinal biomechanics with long-term prosthetic use.