Effects of refractive blur on the multifocal electroretinogram

Area of Science:

• Ophthalmology
• Visual Neuroscience
• Electrophysiology

Background:

• The multifocal electroretinogram (MF-ERG) is a key diagnostic tool for assessing retinal function.
• Previous research suggested a link between refractive error and MF-ERG response density.

Purpose of the Study:

• To investigate the influence of refractive blur on MF-ERG responses in healthy volunteers.
• To determine if refractive error affects MF-ERG amplitudes and latencies.

Main Methods:

• Eight healthy volunteers underwent MF-ERG recordings using VERISTM or Retiscan systems.
• Recordings were performed with corrective lenses (-3, 0, +3, +6 dpt) while adjusting viewing distance to normalize retinal image size.
• MF-ERG responses were analyzed for latency and amplitude differences across various refractive conditions.

Main Results:

• No significant influence of refractive blur on MF-ERG latencies or amplitudes was observed when retinal image size was compensated (P > 0.05).
• This finding was consistent for both central (4 degrees) and peripheral (6-25 degrees) recording areas.
• A minor influence on peripheral amplitudes in one group (Group B) was noted, potentially due to adaptation during successive recordings.

Conclusions:

• Refractive blur does not significantly alter MF-ERG responses when retinal image size is controlled.
• MF-ERG testing can be reliably performed across a range of refractive errors without correction, provided image size is normalized.
• Differences observed between recording systems highlight the importance of system-specific standardization.