The Effects of Hypertension on the Retina

Hypertension is a medical condition where an individual’s blood pressure is higher than normal. It is a common occurrence, with 10 million cases observed in India every year. The chronic disease can majorly impact other organs in the body, including the eyes. Over time, the retina’s blood vessels could be damaged, putting pressure on the optic nerves, and causing vision problems. This is known as Hypertensive Retinopathy (HR).

Dr. Gowthami Kolla, M.S (Ophthalmology), Consultant at MaxiVision Super Specialty Eye Hospitals, Hyderabad shares her valuable knowledge on this condition.

1. What are the types of hypertension?

Primary hypertension is characterised by a 140/90 reading on at least two subsequent visits.

Secondary hypertension may be caused by an underlying disease such as primary hyperaldosteronism, Cushing’s syndrome. pheochromocytoma. Renal vascular or renal parenchymal disease, coarctation of aorta, or hyperthyroidism

Malignant hypertension is a rare condition that causes blood pressure to increase suddenly and rapidly by elevating the blood pressure greater than 200 mg hg systolic and 140 mm hg diastolic, leading to interference with vision along with other systemic findings. This is a potentially life-threatening condition. It needs emergency treatment and admission to hospital.

2. What are the various causes of hypertension?

A lack of physical activity, stress, obesity, diabetes, high cholesterol, increased salt intake, smoking, and heavy alcohol consumption.

3.  Can you discuss the symptoms of HR?

Patients with chronic HR are usually asymptomatic. Symptoms of malignant hypertension include reduced vision, photopsia, double vision accompanied by headaches. Few patients may present with neurological field loss due to stroke/ CVA secondary to Hypertension.

4. How else does hypertension impact the body?

 Patients with hypertension are at an increased risk for coronary artery disease, renal diseases, and strokes.

5. What is the process of diagnosis for HR?

Diagnosis of hypertensive retinopathy is based on presence of systemic hypertension and examination of retina (by an eye specialist) after dilating the pupil either with direct or indirect ophthalmoscopy and slit lamp examination with 90 d lens. Other tests like fluoresce in angiography are required in malignant hypertension to ascertain the diagnosis or to rule out other similar conditions.

6. How do you treat HR?

Systemic hypertension should be controlled as a primary measure for HR. HR with vision threatening complication may be treated with laser therapy or intravitreal injection of Vascular Endothelial Growth Factor (VEGF) drugs. Malignant hypertension can be managed by drugs like sodium nitroprusside, calcium channel blockers, ace inhibitors, nitro-glycerine, etc.
Too rapid decline in BP can cause damage to the brain and optic nerve, and treatment should be done with caution.