Interocular amplitude differences of the full field electroretinogram in normal subjects

Area of Science:

• Ophthalmology
• Neuroscience
• Clinical Electrophysiology

Background:

• The electroretinogram (ERG) is a key diagnostic tool for retinal function.
• Understanding normal interocular variability is crucial for interpreting ERG results.

Purpose of the Study:

• To quantify the interocular amplitude response difference of the electroretinogram (ERG) in normal subjects.
• Establish normative data for ERG b-wave amplitude variations between eyes.

Main Methods:

• 79 healthy subjects underwent ERG testing following ISCEV standards.
• Recorded various ERG responses including rod, scotopic, and flicker stimuli.
• Calculated interocular percentage differences in b-wave amplitudes.

Main Results:

• Median interocular percentage differences in b-wave amplitudes ranged from 8% to 11%.
• Mean differences varied from 11% to 14%.
• 95th percentile differences ranged from 27% to 36%.

Conclusions:

• Normal individuals exhibit consistent interocular ERG b-wave amplitude differences.
• Findings support sample size calculations for monocular therapeutic trials.
• Normative data aids in detecting asymmetric retinal diseases.