Hypertensive Vascular Disease - Changes in the Eye (Hypertensive Retinopathy)

Myxoid Tumours of Soft Tissue

Hypertensive Retinopathy:

Elevated systemic blood pressure commonly affects the retina, causing changes that can be readily seen with the opthalmoscope and which relate to the severity of the hypertension.

Features of the hypertensive retinopathy include:

(a) variable degrees of arteriolar narrowing,

(b) hemorrhages in the retinal nerve fiber layer (“flame-shaped hemorrhages”),

(d) fluffy white bodies in the superficial retina (“cotton wool spots”), and

(e) microaneurysms.

In cases of severe hypertension , the retinal arterioles are much narrower than normal, and there is edema of the optic nerve head .

Arteriolosclerosis accompanies long standing hypertension and commonly affects the retinal and choroidal vessels.

The thickened retinal arterioles become attenuated, increasingly tortuous, and of irregular caliber.

At sites where the arterioles cross veins, the veins may appear kinked (arteriovenous nicking) , but the venous diameter is not narrower distal to the compression, an appearance which indicates that the kinked appearance of veins is not due to compression by a taut sclerotic artery. Instead it reflects sclerosis within the venous walls, because retinal arteries and veins share a common adventitia at sites of arteriovenous crossings.

The abnormal retinal arterioles appear clinically as parallel white lines at sites of vascular crossings (arterial sheathing).

The narrowed lumen of the retinal vessels decreases the visibility of the blood column and makes them first appear orange on opthalmoscopic examination (“copper wiring”).

However, eventually as the blood column becomes completely obscured, light reflected from the sclerotic vessels appear as threads of silver wire (“silver wiring”).

Hypertensive retinopathy has been classified according to severity in Grade 1 through 4, with the higher numbers having more serious changes and a poorer prognosis.

Small superficial or deep retinal hemorrhages often accompany retinal arteriolosclerosis.

In malignant hypertension, a necrotizing arteriolitis, with fibrinoid necrosis and thrombosis of the precapillary retinal arterioles, occurs.

Visit:Normal histology and diseases of the retina ;Retinal Occlusovascular Disease ; Central Retinal Artery Occlusion ; Central Retinal Vein Occlusion ; Hypertensive Retinopathy.

The eye in hypertension.Lancet. 2007 Feb 3;369(9559):425-35

Hypertension has a range of effects on the eye. Hypertensive retinopathy refers to retinal microvascular signs that develop in response to raised blood pressure. Signs of hypertensive retinopathy are frequently seen in adults 40 years and older, and are predictive of incident stroke, congestive heart failure, and cardiovascular mortality--independently of traditional risk factors. Hypertension is also a major risk factor for the development of other retinal vascular diseases, such as retinal vein and artery occlusion, and ischaemic optic neuropathy. High blood pressure increases the risk of both development of diabetic retinopathy and its progression. Adequate control of blood pressure has been proven in randomised clinical trials to reduce vision loss associated with diabetic retinopathy. Finally, hypertension has been implicated in the pathogenesis of glaucoma and age-related macular degeneration. Recognition of the ocular effects of blood pressure could allow physicians to better manage patients with hypertension, and to monitor its end-organ effects.

Light and electron microscopic studies on human retinal blood vessels of patients with sclerosis and hypertension.Int Ophthalmol. 2005 Aug-Oct;26(4-5):151-8. Epub 2007 Feb 9.

PURPOSE: To correlate the ophthalmoscopic and histological findings on human retinal blood vessels of patients with sclerosis and hypertension, respectively. METHODS: Ophthalmoscopy, light microscopy, and transmission and scanning electron microscopy with histochemical staining were performed on eyes obtained from patients with a malignant orbital tumor, with absolute glaucoma, or with hypertensive retinopathy. RESULTS: The retinal arteries in aged patients with ophthalmoscopic sclerotic blood vessels had walls in which the smooth muscle cells had been replaced by collagen fibers, proteoglycan filaments, and ruthenium red-positive materials. The venous blood columns were hidden by numerous swollen nerve fibers and extending Muller cell processes. In a patient with accelerated hypertensive retinopathy, some of the muscle cells in the arteriolar walls were edematous. Focal and generalized narrowing of the retinal arteries appeared to be caused by a true functional constriction of the smooth muscle cells in the walls. CONCLUSIONS: The ophthalmoscopic signs, such as reflection of the retinal arterial blood column and crossing phenomena, were supported by sclerotic manifestations clearly visible upon histological examination. There were some organic changes in the retinal arteries in a patient with accelerated hypertensive retinopathy, but the ophthalmoscopic narrowings appeared to result from a functional constriction of the smooth muscle cells in these vessels.

Hypertensive retinopathy signs as risk indicators of cardiovascular morbidity and mortality.Br Med Bull. 2005 Sep 7;73-74:57-70. Print 2005

Hypertensive retinopathy has long been regarded as a risk indicator for systemic morbidity and mortality. New population-based studies show that hypertensive retinopathy signs are strongly associated with blood pressure, but inconsistently associated with cholesterol and other risk factors of atherosclerosis. Mild hypertensive retinopathy signs, such as generalized and focal retinal arteriolar narrowing and arteriovenous nicking, are weakly associated with systemic vascular diseases. Moderate hypertensive retinopathy signs, such as isolated microaneurysms, haemorrhages and cotton-wool spots, are strongly associated with subclinical cerebrovascular disease and predict incident clinical stroke, congestive heart failure and cardiovascular mortality, independent of blood pressure and other traditional risk factors. These data support the concept that an assessment of retinal vascular changes may provide further information for vascular risk stratification in persons with hypertension.

Retinal microvascular abnormalities and their relationship with hypertension, cardiovascular disease, and mortality.Surv Ophthalmol. 2001 Jul-Aug;46(1):59-80

Retinal microvascular abnormalities, such as generalized and focal arteriolar narrowing, arteriovenous nicking and retinopathy, reflect cumulative vascular damage from hypertension, aging, and other processes. Epidemiological studies indicate that these abnormalities can be observed in 2-15% of the nondiabetic general population and are strongly and consistently associated with elevated blood pressure. Generalized arteriolar narrowing and arteriovenous nicking also appear to be irreversible long-term markers of hypertension, related not only to current but past blood pressure levels as well. There are data supporting an association between retinal microvascular abnormalities and stroke, but there is no convincing evidence of an independent or direct association with atherosclerosis, ischemic heart disease, or cardiovascular mortality. New computer-related imaging methods are currently being developed to detect the presence and severity of retinal arteriolar narrowing and other microvascular characteristics. When reliably quantified, retinal microvascular abnormalities may be useful as risk indicators for cerebrovascular diseases.