Hypertensive retinopathy refers to damage to the retina of the eye that is caused by high blood pressure. The retina is the light-sensing layer of nerves at the back of the eyeball.

What is going on in the body?

The heart, blood vessels, brain, and kidneys control blood pressure. Blood pressure is also controlled by the amount of fluid and salt in the body. Certain hormones in the body can affect both blood vessels and body fluids. The force of the contraction of the heart can also affect blood pressure.

In most people with high blood pressure, the cause is unknown. In this case, high blood pressure is called primary, or essential, hypertension.

When blood pressure is very high for a long period of time, the small blood vessels in the eye undergo a number of changes. The vessels narrow and become constricted in places. Tiny amounts of fluid leak from the blood vessels in the retina. Vision worsens as more and more of the retina is affected by these changes. Sharpness of vision decreases significantly when the central retina, or macula, suffers changes.

What are the causes and risks of the condition?

Most cases of high blood pressure have no known cause. Some people, however, have risk factors that make them more prone to the disease. When not properly treated, high blood pressure causes damage to the small blood vessels in the eyes as well as to the kidney, heart, and brain.