Flash visual evoked potentials (FVEP) in various stimulation conditions

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Technology

Background:

• Flash visual evoked potentials (FVEP) are crucial for assessing visual pathway function.
• Standardization of FVEP testing is essential for reliable clinical interpretation.
• Various stimulators, including Ganzfeld bowl (G), Mini Ganzfeld (MG), and Flash Goggles (GG), are used for FVEP elicitation.

Purpose of the Study:

• To compare FVEP P2 component amplitudes and latencies elicited by G, MG, and GG stimulators.
• To evaluate the effect of eye state (open vs. closed) on FVEP parameters across different stimulators.

Main Methods:

• Seventeen volunteers underwent FVEP testing using G, MG, and GG devices.
• Stimulation parameters (intensity, frequency, filters) were standardized for each device.
• P2 amplitude and latency were analyzed using the Wilcoxon matched-pairs signed-rank test.

Main Results:

• Significant differences in P2 amplitude and latency were observed between the G, MG, and GG stimulators (p < 0.05).
• Eye closure significantly altered FVEP P2 latency for MG and both latency and amplitude for GG.
• Mean P2 amplitudes varied: G (13 µV open, 11 µV closed), MG (7 µV open, 8 µV closed), GG (10 µV open, 8 µV closed).
• Mean P2 latencies varied: G (129 ms open, 127 ms closed), MG (114 ms open, 125 ms closed), GG (110 ms open, 121 ms closed).

Conclusions:

• FVEP P2 parameters elicited by G, MG, and GG are not directly comparable due to significant differences.
• Eye closure influences FVEP P2 latency and amplitude, necessitating consistent methodology.
• The findings highlight the need for standardized protocols when using different FVEP stimulators in clinical practice.