Effects of constant and flickering light on retinal metabolism in rabbits.

PURPOSE

To characterize the glucose metabolism in the rabbit retina.

METHODS

An artery and a vortex vein were cannulated. Arteriovenous differences in oxygen, lactate and glucose concentrations, and blood flow were determined during either 1) darkness and light, or 2) light and 4 Hz flickering light.

RESULTS

In darkness, oxygen consumption, glucose consumption, and lactate formation were 0.122 +/- 0.014, 0.204 +/- 0.015 and 0.160 +/- 0.023 micromol/min (mean +/- SE), respectively. Constant light reduced oxygen consumption insignificantly, and had no effect on glucose consumption. Hyperoxia did not affect the lactate formation. Flickering light increased the glucose consumption and lactate formation by 15-20%.

CONCLUSIONS

In rabbits, 10% of the glucose consumed is oxidized, 40-50% is metabolized to lactate and the rest is used for other purposes. The glycolysis is primarily aerobic. Flickering light increases the glucose metabolism, constant light having little effect.