When blood pressure is high (a condition called hypertension High Blood Pressure High blood pressure (hypertension) is persistently high pressure in the arteries. Often no cause for high blood pressure can be identified, but sometimes it occurs as a result of an underlying... read more 
), the retina may become damaged. Hypertension damages the small blood vessels in the retina, causing their walls to thicken, which decreases the amount of blood that can flow through them. As a result, the blood supply to the retina is reduced. Patches of the retina may become damaged because the blood supply is inadequate.
As hypertensive retinopathy progresses, blood may leak into the retina. These changes lead to a gradual loss of vision, particularly if they affect the macula, the central part of the retina. Even mild hypertension may damage the retinal blood vessels if it goes untreated for years.
If blood pressure becomes dangerously high (called hypertensive emergency Treatment of hypertensive urgencies and emergencies High blood pressure (hypertension) is persistently high pressure in the arteries. Often no cause for high blood pressure can be identified, but sometimes it occurs as a result of an underlying... read more ), the retinal veins can become dilated and twisted, and the optic disk (where the optic nerve meets the retina) may swell (called papilledema Papilledema Papilledema is a condition in which increased pressure in or around the brain causes the part of the optic nerve inside the eye to swell. Visual symptoms may be fleeting disturbances in vision... read more ).
Diagnosis of Hypertensive Retinopathy
A doctor's examination of the eye
Using an ophthalmoscope, doctors can observe the typical appearance of the retina in people with high blood pressure. The amount of damage to the retinal blood vessels tends to correlate with the amount of damage to blood vessels in other organs affected by hypertension, such as the brain, heart, and kidneys. When blood pressure is extremely high, doctors may be able to see swelling of the optic disk (called papilledema Papilledema Papilledema is a condition in which increased pressure in or around the brain causes the part of the optic nerve inside the eye to swell. Visual symptoms may be fleeting disturbances in vision... read more ), indicating the need for immediate treatment (see table Classification of Blood Pressure in Adults Classification of blood pressure High blood pressure (hypertension) is persistently high pressure in the arteries. Often no cause for high blood pressure can be identified, but sometimes it occurs as a result of an underlying... read more ).
Treatment of Hypertensive Retinopathy
Measures to treat high blood pressure
The goal of treatment for hypertensive retinopathy is to lower blood pressure long term. Rarely, when high blood pressure is severe and life threatening, treatment may be needed immediately to save vision and avoid other complications, including stroke, heart failure, kidney failure, and heart attack.
More Information
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
National Eye Institute: A resource for learning about eye health (in English and Spanish) for adults and children, as well as access to outreach campaigns. Simply type in the appropriate search term.
