1994 Volume 13 Issue 3-4 Pages 3-4_155-3-4_164
This work was an attempt to establish methods for examining ocular functions in animals, which may be used in experiments to determine ocular toxicity of drugs under development.
In the first experiment, the refraction of the eye was measured in the cynomolgus monkey. After dark adaptation for 10 minutes, the refraction was measured under general anesthesia with an autorefractometer for human use. The refraction was distributed in the range between +1.5 and -1.75 diopters (D) averaging -0.301±0.790 D, which coincides with that of young humans. The diurnal fluctuation was not obvious. When the pupil was dilated by instillation of sympathomimetic mydriatics such as phenylephrine, the refraction showed no change; but when parasympatholytic mydriatics such as atropine or tropicamide were used, the refraction shifted in the direction of hyperopia by 0.6-1.1 D. These phenomena also coincided with those in humans. We have thus determined that this method can be used in experiments with the monkey.
In the second experiment, the c-wave of the electro-retinogram (ERG) was measured in the same monkey under general anesthesia after dilatation of the pupil. In 41 of 66 animals, or in 62%, a positive c-wave as seen in humans was recorded with good repetition. The mean potentials and latencies were 267.1±44.9μV and 7.9±0.1 sec in males and 337.3±44.4μV and 8.0±0.1 sec in females, respectively. The remaining 25 or 38% of the animals showed a negative c-wave. These two types of c-wave were individual-dependent. Thus we have determined that the measurement of c-wave can be used in experiments in the monkey for the examination of function of the retinal pigment epithelium, provided that individuals with a positive c-wave are selected for the experiment.
