A meta-analysis of clinical electro-oculography values

Area of Science:

• Ophthalmology
• Neuroscience
• Clinical Electrophysiology

Background:

• The electrooculogram (EOG) is a key clinical test in visual electrophysiology.
• Standardized normal values are essential for accurate EOG interpretation.
• Existing EOG studies vary in methodology, necessitating a consolidated reference range.

Purpose of the Study:

• To systematically review published electrooculogram (EOG) studies.
• To derive a comprehensive range of mean normal clinical EOG values.
• To establish reference data adhering to International Society for Clinical Electrophysiology of Vision (ISCEV) standards.

Main Methods:

• A systematic literature review of EOG studies published between 1967 and February 2017 was conducted.
• Nine peer-reviewed articles meeting ISCEV standard criteria (30° saccade, specific luminance, >10 subjects) were included.
• Inverse variance-weighted meta-analysis was used to calculate mean values for key EOG parameters.

Main Results:

• Mean light peak/dark trough (LP:DT) ratios were derived: 2.35 (dilated) and 2.37 (undilated).
• Mean amplitudes for light peak (LP) and dark trough (DT) were 835 µV and 358 µV, respectively.
• Mean time to LP was 8.2 min, and the mean fast oscillation (FO) peak-to-trough ratio was 1.13.

Conclusions:

• This meta-analysis successfully generated a reference range of normal mean electrooculogram (EOG) values.
• The derived values provide a valuable resource for clinicians using the ISCEV standard for EOG.
• This methodology can be applied to create similar datasets for other visual electrophysiology tests.