By Dr Anusha Venkataraman,

MBBS, MD (Opthalmology), DNB, FICO, FRCS

Gone are the days when our forefathers toiled in the fields all through the day; our grandmothers did all the household chores and the children at home did not have swanky gadgets to be couched potatoes. Gone are the days when the kids of the home ventured out to play with friends on the not-so-crowded or polluted streets and those days when mothers used to brandish sticks to bring them back home to finish their daily homework. And, the entire family had good home-made food after a hard day's work unlike the frequent fast foods of these days, and hence maintained a healthy lifestyle. This busy lifestyle, technological advancements and stressful workplaces are taking a toll on the mind, body and soul. Diabetes, hypertension and cardiac problems have now become a common ailment in almost every household.

Normal blood pressure is defined as an average reading no higher than 120/80 mm Hg. A reading of 140/90 or higher is considered high blood pressure, and anything in between is considered "pre-hypertension", which does not show any clear symptoms. High blood pressure will put you at risk of developing a number of health disorders, including those that affect the heart, brain, kidneys, arteries – and the eyes. 

Hypertensive retinopathy is the name given to damage to the retina, as a result of high blood pressure. The retina is the layer of tissue at the back of the eye that works like ‘film’ in a camera. It plays such an important part in a person’s vision that any damage to it is considered serious.

What causes hypertensive retinopathy?

If you have high blood pressure, this can lead to the narrowing of the tiny, delicate vessels that supply blood to the retina. This damage can lead to the loss of clarity in your vision. The higher your blood pressure and the longer it has been elevated, the more damage you risk. Other factors can also contribute to hypertensive retinopathy including diabetes, high cholesterol and smoking. All of these issues can increase the risk of damage and, potentially, cause vision loss.

Treatment

The only way to treat hypertensive retinopathy is to control your blood pressure and ensure that it doesn’t become too high. Lifestyle modifications and a proper diet along with appropriate drugs helps to control hypertension effectively

Symptoms of hypertensive retinopathy

Unfortunately, if you are suffering hypertensive retinopathy you may not realise it, as the symptoms aren’t always obvious. However, there are a few signals that may indicate you are suffering from the condition:

• Double vision or dimmer-than-usual vision

• Headaches

• Visual disturbances, or sudden vision loss

All these signs must be dealt with immediately.

Diagnosing hypertensive retinopathy

Your eye surgeon will use an instrument known as an \ophthalmoscope to check for any sign that the blood vessels in the eye have narrowed, or whether there are signs of fluid leaking from the blood vessels. Then, he will assess the degree of damage. The severity of hypertensive retinopathy varies. Diagnosis is provided in ‘stages’: 

Grade 1. At the minimum level, there may be no obvious symptoms and the narrowing of your arteries can be barely detectable. 

Grade 2. The narrowing of your arteries is detectable. You may also be experiencing visual irregularities. 

Grade 3. There may be a number of changes in the blood vessels, leakage from the blood vessels and swelling elsewhere in the retina. 

Grade 4. At this level, the hypertensive retinopathy may include swelling of the optic nerve and the centre of the retina – the macula. This can cause vision loss. 

Hypertension is also a major risk factor for many other potential blinding conditions such as Retinal Vein Occlusion, Mixed retinopathy and Ischaemic optic neuropathies.

Your ophthalmologist may use Ocular Coherence Tomography(OCT) to diagnose any swelling at the macula which is the most sensitive area of the retina and may use a fluorescent dye and a specialised camera (a fluorescein angiography) to examine the condition of the blood vessels. 

Outcome

The retina will usually recover if the blood pressure can be controlled, but a grade 4 level of retinopathy is likely to involve permanent damage to the optic nerve, or macula. Severe (grade 4) sufferers of retinopathy may also have other health issues such as heart and kidney problems, and are at a greater risk of having a stroke.  If you suffer from high blood pressure and notice any signs of vision loss or headaches, urgent medical attention is required.

Summary

If you suffer from high blood pressure, this can be a chronic medical condition. See your physician, who will help you to take steps to control your blood pressure – this will include following a healthy diet and exercise. If you suffer from high blood pressure, get your eyes screened by your ophthalmologist immediately.

Dr Anusha Venkataraman, MBBS, MD (Opthalmology), DNB, FICO, FRCS, is Head of Dr Agarwal’s Retina Foundation. She is a specialist in Retina related eye problems and has performed several pioneering surgical procedures in this area