THE retina is a transparent layer at the back of the eye that receives visual information and converts it to electrical impulses which is transmitted to the brain via the optic nerve.

The retina is analogous to the film at the back of a traditional film-based camera. The blood supply of the retina is predominantly the central retinal artery while the blood flows out via the central retinal vein. Both these blood vessels travel along the optic nerve, which is located at the back of the eye.

Retinal vein occlusion (RVO) is a common cause of painless visual loss that occurs suddenly and can lead to severe loss of vision.

It occurs in about 0.5% of the population, so in Malaysia, it is estimated that more than 100,000 people will have this problem. It is more common in patients above the age of 50 years.

There are two main types of RVO – central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). BRVO is twice more common than CRVO. Visual loss occurs due to swelling in the macula (macula oedema), which occurs in both these types of RVO.

The macula is the most important part of the retina as it detects very fine detail and colour and any damage to it will cause reduction in our vision.

What Causes Retinal Vein Occlusion?

RVO occurs due to blockage of the vein. This usually happens when the retinal veins are compressed by the retinal artery next to it. Like all arteries in the body, the retinal artery naturally thickens with age, especially if we have diseases like hypertension and high cholesterol levels in our blood.

This thickening of the retinal artery causes narrowing of the retinal vein which is usually located next to the artery. There is reduction of blood flow in the retinal vein leading to blood clot formation and finally total blockage of the vein.

When the retinal vein is blocked, the pressure within the vein increases, causing leakage of blood and fluid out into the retina.

The retina also becomes starved of oxygen (ischaemic) and there is an increase in the levels of a growth factor called vascular endothelial growth factor (VEGF). VEGF causes further leakage of fluid from the blood vessels and increases macula oedema.

Sometimes, there is growth of abnormal new blood vessels on the surface of the retina. These blood vessels are fragile and easily bleed into the eye.

These blood vessels can also grow in the front of the eye on the pupil and can bleed and cause raised eye pressure.

This can be very painful and difficult to treat.

What Are The Risk Factors For Retinal Vein Occlusion?

There are several major risk factors for developing RVO. These are: high blood pressure, high levels of serum cholesterol, diabetes, and glaucoma. For patients younger than 50 years old, they often have blood clotting diseases like high serum homocysteine and antiphospholipid syndrome.

In females, the use of the oral contraceptive pill is associated with a higher risk of RVO.

Patients who develop CRVO tend to do badly without any treatment. Only 20% of patients have an improvement of vision without treatment.

Most patients (80%) lose significant amounts of their vision with this condition and a large percentage of untreated eyes can also develop glaucoma and bleeding in the eye.

BRVO has a better prognosis than CRVO as the patient’s vision is usually not as badly affected. If there is macula oedema present, the visual acuity does improve with treatment. Less than 1% of patients will develop bleeding in the eye in BRVO.

In a few large population studies like the Beijing Eye Study, RVO was associated with a significantly increased risk of death from cardiovascular disease. Men who developed RVO had a two times increased risk of developing stroke.

As such, when a patient develops RVO, it is often a sign of significant cardiovascular disease like high blood pressure and they are at higher risk of developing heart attacks or stroke in the future.

Prevention of Retinal Vein Occlusion

Patients with high blood pressure, high levels of cholesterol in their blood, and who have diabetes are at increased risk of developing RVO. It is important to ensure that these common diseases are well controlled in order to reduce their future risk of getting RVO.

Patients with rare diseases like thrombophilia (blood clotting disease) or high levels of homocysteine are also at risk and need good control to prevent it from occurring.

Once a patient has got RVO in one eye, they have a 15% chance over five years of getting it again in the same eye or the other eye. It is important to screen patients for those diseases in order to treat them to prevent future occurrences of RVO.

Patients with RVO have a higher risk of death from heart attacks and stroke and it is even more important to treat these systemic diseases, especially high blood pressure, to prevent that from happening.

Excerpt: AsiaOne

False health
There are quite a lot of people in this group. One feels “healthy” because there are no symptoms. A guy suffering a heart attack while playing a game of tennis may not have known a day earlier that he had heart disease, which in fact had existed years before. The abruptness of the episode is just the end-point of a disease that has been lurking in him.

Similarly, by the time cancer is detected by conventional methods, the sufferer is already harbouring a billion tumour-stricken cells. At the early stage of false health, there are no symptomatic warnings. The irony is that many are aware of the need to undergo routine medical screening and are actually concerned about their health.

Medical tests are meant to diagnose diseases. A normal test result is reassuring but does not guarantee true health, thus many people with the perfect report may erroneously carry a false sense of security. The above mentioned conditions are not specific entities by themselves but related to the root cause of poor lifestyle choices and bad diet.

Sixty-five thousand people died last night. It’s the same number today, and tomorrow. Why are there no headlines?

What kind of horrible plague am I ranting about? They are the silent killers, known as degenerative diseases.

We do not notice them because they are like wear and tear, akin to stealth raiders of our health. After years of straining the engine, the car will eventually break down, as does the body.

Poor health
Like a river flowing downstream, false health will lead to poor health, which is synonymous with “disease”. People in poor health frequently visit their doctors and need long term drugs. Ironically, this is known as secondary prevention, that is, they manage to avoid drastic complications but they live with chronic diseases like high blood pressure and diabetes.

These diseases need medical attention that includes pharmacologic intervention, which forms part of the treatment regime. However, despite the wide array of new and old drugs, heart attack is still the No.1 killer.

Drugs are therefore not the only answer. Taking prescribed medications without a disciplined change in lifestyle and diet falls short of the ideal 6/4/2010 Heal thyself http://thestar.com.my/health/story.asp… 2/4 treatment plan.

The worst situation is to be in the category of end-stage disease. Chronic heart failure, paralysed by a stroke, advanced metastatic cancer, on dialysis, dementia … the grim list goes on.

The bad news is this not only afflicts the elderly, but more and more so, the younger generation. The good news is these diseases that annually kill people around the world in numbers equal to Malaysia’s population can be prevented.

True health
If we are blessed with 100 years of life, we would wish for 100 years of good health, living a meaningful life. Getting a stroke at 50 and spending the next 30 in bed is not an attractive idea. Quality is more important than quantity. I would strive to add life to my years and not just years to life.

Unfortunately, how many of us are truly healthy? True health by definition is not merely the absence of symptoms but the absence of disease. In the realm of modern lifestyles, with fast foods, fake foods, highly processed meals devoid of nutrients, stress, radiation, chemicals and toxins assaulting us, it’s no wonder our health is under attack.

We are in a war zone, and quite unknowingly, caught in a cross-fire. As in baking, there is a specific recipe necessitating certain ingredients and cooking temperature to make the perfect pastry. In health, too, there is a formula to good health and one for bad. It is a choice we have to make.

We understand the concept of insuring our car, our house, our life, and even our maids in the event they run away. We certainly need to insure our health. Unfortunately, this is one insurance no one can buy, simply because there is there is no such product for sale.

One has to earn it through exercise, attitude, recreation and nutrition (EARN). Accumulating one billion ringgit sure means a lot of zeroes. The digit one represents our health. Lose that and all the wealth in the world comes to naught.

Taking charge of our health is holding destiny in our hands as we have a choice to make. To live life by default or by design.

True health is like the balls in the hands of a circus juggler. A mistimed act can result in the balls falling astray. A skillful performer gets it back in the air. If we are unlucky, we may never find the balls again. I hope you won’t lose yours.

Excerpt: TheStar