[Measurement of electrooculogram in the cat]

In humans, the light peak/dark trough ratio (L/D ratio or Arden ratio) of the electrooculogram (EOG) is conventionally used as an index to estimate the function of the retinal pigment epithelium, but it is rarely in animals. We obtained stable EOG recording in the cat under general anesthesia during light and dark adaptations by applying mechanical forced duction of approximately 3.0 mm in width to one eye of an animal. In five animals, voltages of the dark baseline, the light peak, and dark trough were 580-1,800 (mean, 1,312 microV), 825-2,660 microV (mean, 1,881 microV) and 415-1,480 microV (mean, 1,030 microV), respectively. The L/D ratio in the five animals was 1.70-1.99 (mean, 1.83), similar to that in humans. The present results suggest that the EOG recording by forced duction in experimental animals can be developed into another method to evaluate the retinal pigment epithelial function, particularly to evaluate its potential disorder induced by fluoroquinolones.