High blood pressure can damage blood vessels in the retina. The retina is the layer of tissue at the back part of the eye. It changes light and images that enter the eye into nerve signals that are sent to the brain.
The higher the blood pressure and the longer it has been high, the more severe the damage is likely to be.
You have a higher risk of damage and vision loss when you have diabetes, high cholesterol level, or you smoke.
Rarely, blood pressure readings suddenly become very high. However, when they do, it can cause severe changes in the eye.
Other problems with the retina are also more likely, such as:
Most people with hypertensive retinopathy do not have symptoms until late in the disease.
Symptoms may include:
- Double vision, dim vision, or vision loss
Sudden symptoms are a medical emergency.
Exams and Tests
Your health care provider will use an ophthalmoscope to look for narrowing of the blood vessels and signs that fluid has leaked from blood vessels.
The degree of damage to the retina (retinopathy) is graded on a scale of 1 to 4:
- Grade 1: You may not have symptoms.
- Grades 2 to 3: There are a number of changes in the blood vessels, leaking from blood vessels, and swelling in other parts of the retina.
- Grade 4: You will have swelling of the optic nerve and of the visual center of the retina (macula). This swelling can cause decreased vision.
A test used to examine the blood vessels may be needed.
People with grade 4 (severe retinopathy) often have heart and kidney problems due to high blood pressure. They are also at higher risk for stroke.
In most cases, the retina will heal if the blood pressure is controlled. However, some people with grade 4 retinopathy will have lasting damage to the optic nerve or macula.
When to Contact a Medical Professional
Get emergency treatment if you have high blood pressure with vision changes or headaches.
Kovach JL, Schwartz SG, Schneider S, Rosen RB. Systemic hypertension and the eye. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 3, chap 13.
Levy PD. Hypertension. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 84.
Rogers AH. Hypertensive retinopathy. In: Yanoff M, Duker JS, eds. Ophthalmology. 4th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 6.17.