26. The indocyanine green video angiography in hypertensive choroidopathy

Hypertensive fundus changes are most frequently caused by chronic hyperten­ sion, mainly affect the retina and are well observed with fluorescein angio­ graphy. If hypertensive onset is acute, as in malignant hypertension, choroidal and optic nerve changes are predominant. Choroidal lesions can be actually studied by indocyanine green (ICG) angiography. We examined seven patients with severe hypertension. Two of these patients suffered from chronic hypertension following pre-eclampsia some years earlier. The features observed by ICG angiography are caused by progressive isch­ aemia that affects the choriocapillary bed in malignant hypertensionl. The following angiographic aspects are those which we suggest are related to duration and seriousness of the hypertensive ischaemia: 1. Polygonal and/or triangular perfusion defects of choriocapillary bed, evi­ dent on ICG angiography but not by fluorescein angiography (FA). These ischaemic changes are hypofluorescent, regular and well delimited; they are polygonal in the posterior pole and larger and triangular in the periph­ ery, according to the lobule distribution of choriocapillary nee. 2. Hypofluorescent lesions on ICG angiography that appeared hyperfluores­ cent in FA, variously sized and shaped. Larger arteries were, however, perfused. When ischaemia was persistent the most sensitive ICG studies showed hypofluorescence due to the absence of a choroidal flush, but fluorescein lesions were still hyperfluorescent because of fluorescein leakage and focal necrosis of retinal pigment epithelium (EJshnig's spotS)l ,3 3. Hypofluorescent lesions on both leG and FA, circular or multilobed, well defined, usually in the posterior pole or near main vascular arcades. This is an expression of definitive lack of perfusion caused by capillary necrosis. 4. Choroidal hypofluorescent lines, on both ICG and FA, delimited by hyper­ fluorescent edges assuming the aspect of track; they are mostly radial and in the posterior pole, moving from the optic nerve. They were more clearly visualized and apparently more numerous on ICG than in FA studies. We explain these lesions as choroidal folds: the top part of the fold is hypofluor­ escent because of narrowing of capillaries due to stretching of choroidal layers, while the sloping edges appear hyperfluorescent.