ELECTROPHYSIOLOGICAL STUDIES ON LIGHT DAMAGE IN THE MOUSE RETINA AFTER SODIUM IODATE INJECTION

Acute experimental retinal degeneration was induced in 3-month-old mic e with sodium iodate (NaIO3) injection to investigate the effect of br ight light with electroretinography (ERG). Eight C 57 black male mice were anesthetized. The ERG was recorded before and 24 h after the inje ction of NaIO3. Next, only one eye of each mouse was exposed to a brig ht light of 3.0 x 10(4) 1x white light for 30 min. Ten hours later, ER Gs of both the light-exposed and the unexposed eye were recorded. The amplitudes and peak latencies of the a wave and b wave were measured. The ERG was recorded as both eyes were exposed to stimulating flashes that were given in an increasing order of 0.6 log unit steps from the dimmest flash to produce a detectable ERG. The ERG from the light-expo sed eye showed a distinctly elevated threshold (approx 2.0 log), while the contralateral unexposed eye did not. The peak latencies of both w aves were significantly prolonged by exposure to light. In conclusion, light exposure affected ERG thresholds in mice with experimentally in duced acute retinal degeneration.