[Studies on vision mediated behavioral changes of rat with photic injury]

To evaluate the relationship of visual function and photoreceptor cell loss, and to establish a visual function assessment system based on the observation of optokinetic behavior in rat with photic injury.

SD rats were exposed to (950 +/- 50) lux green light for 3 hours, 12 hours and 24 hours respectively after 24-hour dark adaptation. Then 24-hour dark recovery was followed by 48-hour observation before the eyes were enucleated. Frozen sections were obtained. Slides were stained by HE and rhodopsin immunofluorescent stainings. Vision mediated disturbance of consciousness and pre-pulse response were used to assess the visual function. Optokinetic behavior test was conducted 2 days before and after photic injury. Average velocity of motion were analyzed.

Vision mediated disturbance of consciousness response are gradually weakened; while pre-pulse response is reinforced as the photic injury time increases. The relationship of optokinetic behavior and rat visual function is statistically significant. Optokinetic behavior test shows the average velocity of motion gradually decreases as the injury is aggravated.

Longer light exposure time leads to increased photoreceptor injury, which in turn, causes decrease of visual function in SD rat. Optokinetic behavior test, represented by average velocity of motion, is correlated with rat visual function. Thus, optokinetic behavior test can be used to assess the visual function of SD rat quantitatively.