Integrating Eye-Tracking With Cortical Visual Prostheses in Patients Without Eyes: A Case Study

Area of Science:

• Neuroscience
• Biomedical Engineering
• Ophthalmology

Background:

• Cortical prostheses use electrical stimulation of the occipital cortex to create artificial vision (phosphenes).
• Phosphene location is known to be influenced by gaze position in sighted individuals.
• The effect of intended eye movements on phosphene location in blind individuals without eyes is not well understood.

Purpose of the Study:

• To investigate if intended eye movements modulate phosphene location in a blind patient with cosmetic eyes.
• To assess the feasibility of tracking these eye movements for prosthetic control.
• To determine if gaze position tracking can be integrated into visual prostheses for patients without eyes.

Main Methods:

• A patient with a visual prosthesis implant and cosmetic eyes underwent testing.
• Intended eye movements were recorded using electrooculogram (EOG) and video-based eye tracking.
• Behavioral search experiments were conducted to assess object localization using eye movements.

Main Results:

• Intended eye movements were successfully tracked in a patient with cosmetic eyes.
• A significant correlation was found between eye position and perceived phosphene locations.
• The patient accurately identified object locations using real-time eye movement tracking.

Conclusions:

• Tracking eye movements, even with cosmetic eyes, is feasible for visual prosthesis control.
• Gaze position significantly influences phosphene perception in blind individuals without eyes.
• Incorporating gaze tracking into future visual prostheses is crucial for enhancing artificial vision.