[Study on choroidal blood flow at dark and light adaptation. II. Choroidal blood flow at light adaptation]

The effect of light adaptation on choroidal blood flow (CBF) was studied in albino rabbits. CBF was measured by the hydrogen clearance method. There was no significant change of CBF at light adaptation, in which CBF had been expected to decrease due to decreased oxygen demand of the outer retina. The results showed that light adaptation did not influence CBF, in spite of the close relationship between the outer retina and choroidal circulation. Because of the rich blood flow, the choroidal circulation may not need a reaction mechanism for functional changes of the outer retina.