Choroidal hemodynamics using videoangiography

Abstract

The characteristics of choroidal circulation were studied in 100 healthy subjects and differentiated from pathologically delayed filling of the choroid. The method used was videoangiography, which permits slow-motion analysis of choroidal hemodynamics. The sections of the choroid which fill fastest are the macula region, the peripapillary areas and the lower periphery, followed by the temporal and upper periphery and subsequently the nasal half of the fundus. If the beginning of choroidal filling is delayed for more than 3-3.5 s in any region it is 99% certain that the delay is pathologic. If this time is set in relation to the retinal circulation it approximates the early venous circulation time, i.e., the time in which the laminary venous blood flow reaches the optic disk. Videoangiography confirms that it is not possible to detect any functionally effective links between different choroidal lobuli. Choroidal circulation disorders in the event of occlusion of functional end-arteries are a logical consequence of this. Choroidal filling varies over a broad range: five different types of choroidal filling may be distinguished. The constant patterns of choroidal veins found by Hayreh in monkeys are only partially applicable to humans; the supply pattern of the human choroid must be regarded as considerably more complex.