Electro-oculography records changes in the standing potential between the front and back of the eye as it moves, indirectly assessing retinal pigment epithelium function. It also provides information about eye movement.
Technique
Electrodes are placed near the inner and outer canthi while the patient performs repeated horizontal saccades between fixed targets under dark and light adapted conditions. The ratio of light peak to dark trough, known as the Arden ratio, is calculated.
- Reflects the function of the retinal pigment epithelium and outer retina
- Requires patient cooperation for accurate eye movements
- Testing conditions are carefully controlled for illumination and timing
- Waveforms are averaged to reduce noise
Clinical Use
Electro-oculography is particularly useful in diagnosing conditions such as Best disease and some other macular dystrophies. Abnormal Arden ratios indicate impaired retinal pigment epithelium activity.
- Often performed alongside electroretinography for a complete functional assessment
- Helps differentiate between different hereditary macular disorders
- Serial tests can monitor disease progression
- Interpretation must consider age-related normative data
