[Ocular electrical stimulation: Therapeutic application and active retinal implants for hereditary retinal...

Area of Science:

• Ophthalmology
• Neuroscience
• Biomedical Engineering

Background:

• Electrical stimulation has a historical role in ophthalmology.
• Subthreshold electrical stimulation offers therapeutic benefits for hereditary retinal diseases.
• Suprathreshold stimulation can induce visual perceptions, with potential for image formation using multielectrode arrays.

Purpose of the Study:

• To review the current status and research on therapeutic transcorneal electrical stimulation.
• To discuss challenges, surgical approaches, and visual outcomes of active retinal implants.

Main Methods:

• Overview of transcorneal electrical stimulation and active retinal implants based on published literature.
• Emphasis on clinical applications and patient outcomes.

Main Results:

• Initial studies on therapeutic transcorneal electrical stimulation for hereditary retinal diseases show promising results.
• A large study in retinitis pigmentosa (RP) patients indicated positive trends and electrophysiological improvements.
• Approved retinal implants (Argus II, Alpha-IMS) can enhance visual perception, achieving visual acuities of 0.02 and 0.04 under test conditions.

Conclusions:

• Further in-depth studies with larger patient cohorts are needed to confirm the potential of therapeutic transcorneal electrical stimulation in RP.
• Current active retinal implants face challenges related to technical biostability and limited spatial resolution.