Abstract
Abstract: :
Purpose: To study the possible role of choroidal circulation, circulation, particulary choriocapillary hemodynamics, in developing multifocal posterior retinal pigment epitheliopathy (MPPE) using indocyanine green angiography (ICG). Methods: Subjects were 7 MPPE patients ranging in age from 41-73 years and 5 healthy volunteers of comparable ages. ICG angiography was performed using a modified Topcon ICG video camerasystem (TRC-50IAL). Video images were obtaind for computer-assisted image processing. Subtracted images were made using the early ICG flames with a 0.12-sec time difference. Ninety frames of time-sequential images for a 3-sec period from the initial dye appearance in the choroid) were used to construct an animated image. Results: In healthy eye, initial dye-filling in the choroid appeared in the macula. The fluorescence then extended centrifugally in all directions toward the peripheral fundus with increasing brightness in pulsatile manner. This progression pattern was a common observation in all healthy volunteers. In MPPE eyes, initial dye-filling occurred extra out foveal zone. The fluorescence spread centrifugally unevenly with increasing brightness in a pulsatile manner. The fluorescence pattern differs from healthy control and fluorescence band with one optic disc diameter formed the wave front. Conclusion: An animated video of subtracted images permits evaluation of the flow dynamics at the level of the choriocapillaris. Brightness increase in a subtraction animation of MPPE is not constant; choriocapillary hemodynamics was segmented into two phases. At first brightness increased slowly and suddenly increased. This circulation was repeated with a pulse.
Keywords: 554 retina • 345 choroid