The pathophysiological changes occurring in the area of a chorioretinal burn, as well as the effects of such a burn on the choroidal circulation, have been studied in the rabbit using the technique of fluorescence angiography. Several small burns or a large burn will interrupt the distal choroidal circulation. The extent of the interruption is related to the size of the damaged area. In the areas of minimal to moderate damage, there is rapid fluorescence which is interpreted to be the result of an increase in capillary permeability allowing the fluorescein to stain these areas. In the areas of extensive damage and presumed coagulation of protein, there is a late fluorescence which is interpreted as the result of slow diffusion of fluorescein into the area of occluded choriocapillaries.
Newsom WA, Tredici TJ, Bruce WR. Fluorescence Angiography of Chorioretinal Burns. Arch Ophthalmol. 1967;78(6):753-756. doi:10.1001/archopht.1967.00980030755012