Hypertensive choroidopathy: recognizing clinically significant end‐organ damage

Abstract

A 49-year-old, white man presented with a 2-week history of painless loss of vision in his left eye and dull, pressure-like frontal headache. His blood pressure (BP) was 190/100. He had been on atenolol 50 mg daily for the previous 2 weeks for initial BP of 210/140, but his BP was still not well controlled. He smoked 15 cigarettes per day. A low glomerular filtration rate assessed by creatinine clearance indicated renal impairment. Diabetes mellitus and glucose intolerance were excluded. Duplex ultrasound, a combination of conventional and Doppler ultrasound, demonstrated the structure of his carotid arteries and the blood flow through them to be normal. Neurological examination was unremarkable. Corrected visual acuities (VA) were 1.0 in the right eye (RE) and 0.1 in the left (LE), with no relative afferent pupillary defect. Fundal examination revealed deep grey−yellow spots in both eyes, as well as hyperpigmented spots surrounded by a hypopigmented halo (Elschnig’s spots). In the LE, small pigment epithelial detachments (PEDs) and an exudative retinal detachment (RD) extending through the fovea were seen clinically and captured by optical coherence tomography (OCT). Retinal arteriolar narrowing, vascular tortuosity and arteriolovenous nicking were also identified. Fundus fluorescein angiography (FA) showed decreased perfusion of the choroid at the left macula, accompanied by patchy secondary pigment changes and small PEDs in both eyes. (Fig. 1). (A) Left fundus of a 49-year-old patient with severe hypertension shows deep grey−yellow spots (*). Elschnig’s spots (white arrow), retinal arteriolar narrowing, vascular tortuosity and arteriolovenous nicking, suggesting chronic hypertension, are also evident. (B) Elschnig’s spots are changes in the retinal pigment epithelium (RPE) from non-perfused areas of the choriocapillaris as seen by fluorescein angiography (black arrow). (C) Patchy secondary pigment changes at the macula leaked fluorescein, showing staining of the damaged RPE during the late phase, and accounted for the subject’s poor vision (0.1). (D) Optical coherence tomography of the left macula shows exudative retinal detachment involving the fovea with a small pigment epithelial detachment on the right side, which corresponds with the deep yellow spot (*) in (A). One year later, VA remained at 1.0 RE and 0.1 LE and ophthalmoscopy showed macular pigmentary changes suggestive of choroidal ischaemia and retinal pigment epithelium (RPE) necrosis. The subject’s BP was well controlled and a secondary cause had been ruled out. Severe systemic hypertension is associated with significant end-organ damage, to, for example, the eyes, heart, central nervous system and kidneys, and morbidity. Choroidal lesions are less well recognized than retinal and optic nerve lesions (Luo & Brown 2004), but, as shown here, they have important implications for ocular health and appear to be linked to renal dysfunction. This report clarifies clinical features which will help in the recognition of hypertensive choroidopathy. Hypertensive choroidopathy has been described in association with toxaemia of pregnancy (Kinyoun & Kalina 1986; Patel et al. 2005), systemic lupus erythematosus (Kinyoun & Kalina 1986), disseminated intravascular coagulation (Patel et al. 2005) and thrombocytic thrombocytopenic purpura (Kinyoun & Kalina 1986). In the majority of cases, normal vision is regained (Kinyoun & Kalina 1986). The persistent visual loss in our patient is considered to be the result of choroidal ischaemic damage to the RPE in the central macula. Severe high BP can lead to choroidal fibrinoid necrosis, choriocapillaris non-perfusion, RPE ischaemic necrosis, compromise of the outer blood-retinal barrier and localized PED and/or exudative RD (Kishi et al. 1985). The outer retina and subretinal space in these cases are known to contain protein-rich exudates. Clinically, areas of RPE overlying occluded choriocapillaris appear yellow and leak fluorescein profusely (Elschnig’s spots). With time, the RPE becomes hyperpigmented directly over the occluded choriocapillaris with a margin of hypopigmentation. Healed Elschnig’s spots do not leak fluorescein, but fluorescence transmission through the hypopigmented halo will occur. Elschnig was credited in 1904 with the discovery of the spots which bear his name in severe nephritis. However, similar lesions associated with albuminuria had been reported in the mid-19th century. Occasionally, linear configurations of hyperpigmentation can be seen over choroidal arteries (Siegrist’s streaks) in cases of chronic hypertension. The narrowed arterioles, vascular tortuosity and arteriolovenous nicking in the retinal vessels of our patient suggested chronic hypertension. However, no Siegrist’s streaks were seen. Fibrinoid necrosis has been implicated in the pathogenesis of both hypertensive choroidopathy and nephropathy (Luft et al. 1999). This points to a link between these two entities and suggests they are both indicators of end-organ damage. The presence of choroidopathy in severe hypertension, even in the absence of papilloedema, may indicate a more aggressive intervention, such as intravenous treatment. Shortening the period of elevated pressure and RPE decompensation may improve the visual and general prognosis.