New noncorneal HK-loop electrode for clinical electroretinography

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Neuroscience

Background:

• Clinical electroretinography (ERG) is crucial for diagnosing retinal dysfunction.
• Current electrodes, like gold foil or corneal types, have limitations including fragility, cost, and patient discomfort.
• A need exists for a stable, durable, and user-friendly ERG electrode.

Purpose of the Study:

• To develop and evaluate a novel noncorneal electrode for clinical electroretinography.
• To assess the performance, durability, and usability of the new electrode compared to existing ones.

Main Methods:

• A new noncorneal electrode was designed using a looped thin wire to fit the lower conjunctival sac.
• Electrical contact is established with the scleral conjunctiva via an exposed wire portion.
• Performance was evaluated by recording pattern electroretinograms (PERG) and flash electroretinograms (fERG) and comparing amplitudes and stability.

Main Results:

• The new electrode recorded PERGs with amplitudes similar to gold foil electrodes.
• fERG amplitudes were approximately two-thirds of those recorded by corneal electrodes.
• The electrode demonstrated durability, ease of cleaning, and stability for at least 2 hours without topical anesthetic, with minimal discomfort.

Conclusions:

• The developed noncorneal electrode offers a promising alternative for clinical electroretinography.
• It combines the stability of skin electrodes with the sensitivity of foil/fiber electrodes.
• Its durability, cost-effectiveness, and ease of use make it a practical option for routine ERG testing.