Dr Ben Wild
Overview |
Hypertension, or high blood pressure, refers to a condition where the pressure of the blood pushing outwards onto the artery walls is elevated. The pressure is measured in millimeters of mercury with normal levels being under 120mmHg when the heart has just finished a beat, and under 80mmHg right before the heart beats. Stage 1 hypertension starts at 130/81mmHg. When pressures are 180/120mmHg or higher, this is an emergency. If left untreated, hypertension can lead to heart attack, stroke, heart failure, kidney problems and other health conditions.
A frontal view of a healthy retina.
The most common effect of hypertension on the eyes is hypertensive retinopathy. The constantly high pressure damages the muscles of the arteries. The arteries may then start to shrink, start to block off veins where the arteries and veins cross over each other, start to leak fluid, lead to areas of the retina that lack oxygen, and even swelling of the optic nerve and brain.
A frontal view of a retina with hypertensive retinopathy showing swelling of the optic nerve (yellow circle), hemorrhaging around the nerve, cholesterol and fluid leaking into the macula (yellow spots in dark circle), thin arteries, and copper/silver wire appearance to arteries.
The second most common effect is weakened blood vessels at the front of the eye and a higher occurrence of subconjunctival hemorrhages (popped blood vessels on the whites of the eye).
A frontal view of a healthy eye (top) and an eye with a subconjunctival hemorrhage (bottom).
Less common effects can include damage to the nerves that control the extra-ocular eye muscles responsible for eye movement, retinal detachments from leaking fluid, and others.
Signs and Symptoms |
Signs
Narrow retinal arteries, whitening of retinal arteries, arteries blocking underlying retinal veins, bleeding in the retina, fluid leaking into the retina, cholesterol leaking into the retina, swollen optic nerves, white patch of the retina that look like cotton wool, popped blood vessels on the front of the eye, restricted eye movements.
Symptoms
Often asymptomatic, possibly double vision, decreased vision, floaters.
Causes and Risk Factors |
Causes
Primary hypertension does not have a known cause and gradually progresses over time. Plaque build-up on arterial walls (atherosclerosis) is seen. Secondary hypertension could be from medications, adrenal gland tumors, congenital (birth defect) heart defect, kidney disease, sleep apnea, thyroid problems, unhealthy lifestyle and diet.
Risk Factors
Older age, African ancestry, family history, being overweight, lack of exercise, tobacco/vaping, excessive salt consumption, low potassium, too much alcohol, stress, pregnancy, and more.
Prevention and Treatment |
Prevention
Maintaining a healthy lifestyle with a balanced and nutritious diet.
Treatments
· Anti-hypertensive medications.
· For double vision: temporary prism on glasses or patch one eye.
· For subconjunctival hemorrhage: artificial tears for comfort.
· For retinopathy: usually no further treatment required but for persistent fluid leakage; anti-VEGF injections, non-steroidal anti-inflammatory eye drops.
Prognosis |
Hypertension is very common. It increases the risks of heart attack, stroke, heart failure, kidney problems and other health conditions. Proper treatment can decrease those risks. Most of the effects of hypertension on the eye do not cause any visual disturbances and those that do, are usually not permanent if treated in a timely manner.
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