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How to prevent cataracts?

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Cataracts are a leading cause for blindness worldwide, and an estimated 30% of people over the age of 65 years are visually impaired due to cataracts...

**This article was published in English and has no translation in Malay Language**

By Dr. Dhashani Sivaratnam  

Cataracts are a leading cause for blindness worldwide, and an estimated 30% of people over the age of 65 years are visually impaired due to cataracts in one or both eyes. Cataracts develop when the lens within your eye becomes cloudy. A clear lens is responsible for focusing an image on the retina in order it to be visualized. The development of cataract is commonly associated with advancing age, family history, poorly controlled diabetes mellitus, hypertension, obesity, smoking, prolonged steroid medication, severe short-sightedness, previous eye injury or inflammation.

While you cannot do anything about your age or family history, there are several steps you may take to reduce the risk of cataract formation. Several studies have revealed that cataracts can be prevented just by a healthy diet. A high dietary intake of antioxidants is essential for eye health and the prevention of cataract formation. What are antioxidants? These are substances that occur naturally in plant foods, which help scavenge harmful molecules known as free radicals from within your body.  Free radicals are the natural by-product of normal bodily processes or inflammation, it can also be acquired from pollution, UV exposure, food contaminants, household chemicals and cigarette smoke. These free radicals are responsible for a myriad of degenerative disorders such as cataracts, age-related macular degeneration, heart disease, cancer, stroke, arthritis, diabetes mellitus, asthma and senile dementia to name a few.

Antioxidants are not really the name of a substance but rather a range of substances that protect you from the harmful effect of free radicals. Examples of antioxidants which are important for your eyes include vitamin C and E, beta-carotene, lutein and zeaxanthin. The best way for you to get antioxidants is from food. Vitamin C is a very important antioxidant and is readily available in citrus fruits, berries, broccoli, tomatoes, papaya, guava and peppers (red, yellow, green). While, vitamin E is found in nuts and seed, sunflower and other vegetable oils, avocados and green leafy vegetable. Beta-carotene is found in brightly coloured fruits and vegetables, green leafy vegetables such as spinach and kale.  Other foods which are also a rich source of antioxidants include lentils and legumes, green tea, dark chocolate, goji berries, pomegranates, turmeric, ginger, cinnamon and clove. There is no set recommended daily allowances (RDA) for antioxidants, but a high intake of fresh plant-based produce is considered healthful.

The use of antioxidant supplements is not recommended. The American Institute of Cancer Research and the National Institute of Health (NIH) have found that there is no protective benefit in taking antioxidant supplements, infact, it may even increase the risk for cancer and lead to birth defects. The Canadian College of Family Physician’s food guide encourages you to enjoy vegetarian meals often. A typical meal should contain 75% of plant food. Meat should only garnish your plate and should not be the focus of the meal. Pick a variety of coloured fruits and vegetables every day. Eat at least one dark green and one orange vegetable daily. Stir-fry or steam your vegetables to prevent excess antioxidant losses into the water. Include whole grains, nuts, seed, beans, peas and lentil often into your meals.

Smoking is another important risk factor to avoid. Smoking leads to accumulations of heavy metals like cadmium in the lens which will lead to cataract formation. Latest research shows that the risk of cataracts triples among heavy smokers and doubles in moderate smokers when compared to non-smokers. 

Heavy alcohol consumption has also been shown to increase the risk of cataract. Research done by Boston University found that consuming more than two drinks per day (20gms of alcohol) markedly increased the risk of cataracts. However, you do not need to give up that glass of wine with dinner as two standard size drinks of alcohol has been shown to be protective compared to those who never drink at all.

It is also essential to keep your blood sugar level within the normal range as studies have found that people with poorly controlled diabetes have a higher risk of cataract. When your blood sugar is high, sugar in the form of sorbitol collects in the lens of your eyes and causes it to swell. This will cause blurring of vision. Long term and recurrent lens swelling will damage the lens fibres leading to cataract formation.

Last but not least, using sunglasses can cut your risk of getting a cataract. Ultraviolet light damages the proteins in your lens, therefore look for protective sunglasses that block 99% of UVA and 100% of UVB rays. It should also filter out at least 75 to 90% of visible light. A grey tint is helpful when driving, and the frame should ideally fit close to your eyes.

Cataracts are commonly associated with ageing. Visual impairment in the elderly will decrease their ability to perform activities of daily living such as walking, reading, watching TV and even regular household chores. Therefore, increasing the risk of depression and anxiety as their ability to perform their hobbies or favourite recreational activities becomes difficult.

Poor vision among the elderly is also associated with an increased risk of falls and fractures. Therfore, while self-care measures may help prevent or delay the onset of cataract formation. Once a cataract has formed, there is no other proven way to treat it other than cataract surgery.

This can be done as a quick out-patient procedure with minimal risk of complication.  Recovery of vision is rapid, and there is little disruption to the activities of daily living. If you do develop symptoms suggestive of a cataract, do visit your ophthalmologist immediately for further advice.

Dr. Dhashani Sivaratnam  

Senior Lecturer

Ophthalmology unit

Surgical Department

Faculty of Medicine and Health Sciences