Fundus lesions in malignant hypertension. I. A pathologic study of experimental hypertensive choroidopathy
S. Kishi, M. O. Tso and S. S. Hayreh
Experimental hypertensive choroidopathy was studied in 29 eyes from 15
monkeys in which accelerated renovascular systemic hypertension developed
after a modified Goldblatt procedure. We followed up the animals from five
days to 21 months to examine clinically and histopathologically the
spectrum of the pathologic process. The pathologic features of hypertensive
choroidopathy in our animals may be categorized into three phases: (1)
Acute ischemic phase: The initial change in the choroidal vasculature was
constriction of arterioles, which leads to focal necrosis of the
choriocapillaris and the retinal pigment epithelium and focal subretinal
exudate. (2) Chronic occlusive phase: Occlusive changes involving arteries,
arterioles, and choriocapillaris occurred later. (3) Chronic reparative
phase: With time, recanalization took place at all levels of the choroidal
vasculature. The subretinal fluid was reabsorbed, leaving diffuse patchy
depigmentation of the retinal pigment epithelium, which followed lobular
arrangement of the choriocapillaris. Arteriolization of the
choriocapillaris developed; this seems to be a defense mechanism to
withstand the elevated systemic blood pressure.
