Choroidal blood flow as a heat dissipating mechanism in the macula.

We studied the possible role of the choroidal circulation in stabilizing the temperature environment of the retina and the retinal pigment epithelium. Temperature measurements were taken from the retina and choroid of the monkey eye while the ambient illumination and choroidal blood flow were varied. The results showed that the choroidal circulation plays a significant role in dissipating heat generated by the focusing of light at the macula and suggest that this function may be a primary reason for the relatively high values of choroidal blood flow.