Hypertensive retinopathy is a complication of high blood pressure (hypertension) affecting the eyes, specifically the retina. High blood pressure is very common, and it’s uncommon not to have it once a person hits a certain age. It’s one of the leading causes of mortality and morbidity in the world today.
An important point to be considered here is that this condition is dangerous, as the patient does not realize that they are suffering from this condition until it may become too late. This is also the reason why this disorder is also called the silent killer.
When talking about hypertension, people may associate it with coronary heart disease, cerebrovascular disease, and renal disease. The heart, brain, and kidneys are often targeted, but most people don’t think of the eyes being a target of high blood pressure.
Hypertensive retinopathy is a disease of the retinal and choroidal vasculature due to severe acute or chronic hypertension. Hypertensive retinopathy is not reliably symptomatic, but it’s indicative of an underlying problem. Hypertensive retinopathy affects both the retinal and choroidal circulation.
Retinal vasculature & choroidal vasculature
Retinal vasculature and choroidal vasculature refer to the two systems of blood vessels feeding your retina. The inner retina is supplied with blood by the retinal vasculature, which are two branches of the ophthalmic artery; (1) the central retinal artery and (2) the posterior ciliary arteries.
The retinal vasculature is autoregulated. Auto-regulated means that when your systemic blood pressure goes up or down, the retinal vasculature can expand or contract to keep the blood pressure in the retinal vasculature at a set range. The retinal vasculature loses its autoregulation when diastolic blood pressure exceeds 110-115 mmHg.
The choroidal vasculature blood supply goes to the outer and middle retina and comes from a different branch of the ophthalmic artery called the posterior ciliary arteries. As opposed to the retinal vasculature, the coronal vasculature is regulated by the sympathetic nervous system, by the central nervous system, just like all of the other blood vessels in our body.
Primarily seen in older patients, hypertensive retinopathy has two distinct disease processes, acute hypertensive retinopathy, and chronic hypertensive retinopathy:
Acute hypertensive retinopathy
Acute hypertensive retinopathy may be seen in patients of any age and is typically seen in patients with a severe hypertensive crisis (secondary hypertension.) Which is a sudden spike in blood pressure to 180/120 or higher caused by another medical condition. The causes of secondary hypertension include Hyperthyroidism, pheochromocytoma, pre-eclampsia/eclampsia, drug abuse, and neoplasm.
Generally, the blood pressure must be greater than 200/110 to cause retinopathy. Secondary hypertension damages the retinal and choroidal vasculature (fibrinoid necrosis) and then ischemic necrosis (tissue damage caused by lack of blood.)
Chronic hypertensive retinopathy
Chronic hypertensive retinopathy is an end-organ disease manifestation of hypertension. Seen in older patients with chronic (long-standing) hypertension, it accelerates the development of atherosclerosis.
Atherosclerosis reduces the radius of arterioles because the plaque has increased, and the vasculature must expand to down-regulate the resistance. As the arterioles expand, they compress the venules (smaller blood vessels) and lead to occlusion (blockage) of blood flow to the retina. In advanced stages, visual acuity loss will be present.
Advanced retinopathy can be considered a severe acute case of hypertension, like a hypertensive crisis where your blood pressure is above the 180 over 110 range. Or a patient with chronic hypertension like a 70-year-old man who’s been taking lisinopril for the last 20 years for mild hypertension.
Whether it is severe acute hypertension or chronic hypertension, it basically does the same thing to your retina and eyes. Hypertensive retinopathy itself, though, is not reliably symptomatic. You can have symptoms, but you tend not to have visual changes with hypertensive retinopathy itself. But its pathological presence is indicative of an underlying problem.
Complications of Hypertensive retinopathy
We have learned how high blood pressure can damage the blood vessels, the vascular system supplying blood to the retina. Naturally, if there are damages to your retina, a major component of vision, your vision will be negatively impacted.
The damage that hypertension does to your retina’s blood vessels will limit the retina’s function and put pressure on the optic nerve. As discussed previously, initially, there may be no symptoms. However, in later stages of Hypertensive retinopathy, there can be complications such as:
- Reduced peripheral vision
- Blurring of vision to a deep loss of vision
- Swelling of the eyes
- Bursting of blood vessels
- Double vision with headaches
- Serous detachment of the retina
Diagnosis of Hypertensive retinopathy
If you have systemic hypertension, a retinal specialist can diagnose hypertensive retinopathy by dilating your pupil and using an ophthalmoscope to exam the retina. During the retinal or fundus examination, the doctor will look for well-known signs of the disease. This includes:
Vasoconstriction – generalized or localized narrowing of blood vessels. If severe acute hypertensive retinopathy leads to blockage of small blood vessels going to the retina, they may see “cotton-wool spots,” as they are called.
Leakage – Abnormal permeability of the retinal vasculature can lead to retinal edema, the build-up of fluid in the macula creating flame-shaped hemorrhages, and the formation of hard exudates (flecks made of residues of serous leakage from damaged capillaries.)
Arteriosclerosis – thickening of the blood vessel wall is noted that causes marked changes at arteriovenous crossings.
Hypertensive retinopathy treatment
Treatment for hypertensive retinopathy can only be done by controlling and reducing blood pressure. While an ophthalmologist or medical doctor can prescribe medications to help reduce the systolic and diastolic blood pressure, the patient must make lifestyle and diet changes and do careful monitoring.
If they continue to live the kind of life contributing to their hypertension, like smoking and drinking or being overweight, it can be challenging to overcome. However, if successfully reducing blood pressure to a normal level, the condition can be halted, and the damage may slowly heal.
Get a comprehensive eye examination now!
Don’t wait until you start having symptoms of hypertensive retinopathy to have a complete eye exam. See an ophthalmologist, or even better, a retinal specialist promptly to keep from possibly losing your eyesight.