Cataracts

Cataracts are the leading cause of blindness in the world today, and are the leading cause of impaired vision in New Zealand, with a large percentage of the elderly population exhibiting some signs of this eye lesion. In 2005, the Government in this country pledged to spend an extra $17 million over the next three years in providing a total of up to 7500 more cataracts operations. The NZ Ministry of Health said that by 2007-08 they hoped to be performing more than 12,000 operations a year, a 50 percent increase on 2005. I am not sure of the prevalence of cataracts with the different age groups in NZ, but in America, age-related lens changes have been reported in 42% of those between the ages of 52 to 64, 60% of those between the ages 65 and 74, and an amazing 91% of those between the ages of 75 and 85. My guess is that these figures are similar to here. Are you elderly and reading this article? Chances are they you may well have one cataract. Please get your eyes checked out if you are unsure. Too many elderly citizens fall, and some of these falls may well have been prevented – just by seeing better!

What are cataracts?

The word cataract comes from the Latin word cataracta which basically means "waterfall”.    
                   
As rapidly running water turns white, the term may later have been used to describe the similar whitish appearance of the mature opacities. Opacity means that the lens of your eye becomes clouded, a bit like you are looking at the mirror in your bathroom when you step out of the shower, and you can’t quite clearly see yourself until you wipe the surface. The lens in your eye is situated immediately behind the coloured part of your eye, the iris, and this lens is held in position by tiny ligaments, which conveniently alter its shape for near or far vision."

Cataracts are developmental or degenerative opacities of the lens of the eye, generally characterised by a gradual painless loss of vision. The extent of the vision loss depends on the size and location of the cataract. Cataracts may be located in the center in the superficial layers, in the middle, or in the rear of the lens area. Cataracts are also classified according to their colour, which is consistent with their location and density. Pale yellow cataracts are typically slight opacities; yellow to light brown are consistent with moderate to intense opacities; and by the time they reach a brown colouring, cataracts are very dense opacities – causing quite significant vision loss and even complete blindness.

I have found that when I look into an older patient’s eyes, cataracts can be readily spotted by looking into the pupil with a light shining on it, under some degree of magnification. The pupil has changed appearance somewhat, it is not a nice deep black colour, there appears to be a fogginess or haziness overlaying the pupil. Because cataracts tend to develop slowly over time, you don’t even know your vision has deteriorated that much, until one day somebody literally “cleans your windows”. My mother had the lenses in her eyes replaced in a cataract surgical procedure when she was in her late 60’s.   

I can still remember her telling me that it was like somebody had “wiped the windows clean”, and that she could see so much more clearly. I’ll bet many readers who have had cataract surgery can relate to this one. Remember when they took that patch off your eye – and you went, wow! How amazing!

When you go out at times, isn’t it interesting how many people squint, and hold their hand up to their forehead whilst they are out in the sun? Do you wear sunglasses, particularly when you are at the beach, or near any water or snow?  It is my belief that you really should, the reflective glare can be incredible – and you will causing damage to your vision, as well as your skin (if you still don’t get the “cover up” message)  to some degree. 

Although cataracts have no 100% scientifically proven prevention, many scientists do say that wearing ultraviolet-protecting sunglasses may slow the development of cataracts, in some cases significantly. Exposure to the sunlight with particular reference to the ultraviolet-B radiation spectrum is thought to be one of the leading causes of cataract, particularly in tropical countries. So – shading your eyes throughout your life from ultraviolet light is one of the best measures one can take to prevent cataracts. Brimmed hats are also recommended.

Now that you have read this article so far, when did you have your eyes checked last? I am constantly amazed at how many patients we see in the clinic, who have not had an eye exam in years for some reason or other, no reading test, no pressure test for glaucoma, no peripheral vision test for macular degeneration. No test at all. You don’t know what you have got….until it’s all gone, as the saying goes. What price do you put on your vision? I think you will have to agree – good vision is absolutely priceless, at any age.

Some causes of cataracts

Most cataracts develop due to ageing, but there are potentially many factors which may contribute to cataract formation. What most experts do agree on, is that the actual biochemical cause of cataracts is the inability to maintain a normal concentration of calcium, potassium and sodium ions within the protein cells of the actual lens. Free radical production (some of the causes below, like sunlight, heavy metals, drugs, stress, dietary factors, etc.) has a devastating effect on this incredibly high-metabolically active area. How do we know this?  Well simple, high levels of anti-oxidants in the eye can have a most amazing effect in reducing the risk of cataract development, but more on this later.

 Some of the most plausible causes include:

• Radiation:  A study among pilots in Iceland showed commercial airline pilots are three times more likely to develop cataracts than people with non-flying jobs. Cataracts are also unusually common in persons who spend a great deal of time outdoors (the sun), and those exposed to infrared radiation, such as glassblowers.

• Smoking: But of course you don’t smoke, Healthy Options readers don’t smoke !

• Following trauma: eye injuries, penetrating injuries

• Oxidative stress – free radical production.

• Dietary factors – e.g.; the consumption of large quantities of milk by people who do not efficiently utilise the milk sugar called galactose. This in turn causes a deficiency of the B Vitamin riboflavin (B2). B2 has been found to important in recycling glutathione, which has been found to be very important in keeping cataracts at bay by exerting antioxidant effects in the lens of the eye.

• Obesity: There is much evidence which shows that obese people have a 200% greater likelihood of developing cataracts compared to normal, healthy humans.

• Diabetics (Type 2): are more prone to cataracts due to the inherent inability of a diabetic to properly metabolise carbohydrates. Excessive levels of a sugar (galactose – a component of lactose, the milk sugar) can accumulate within the eye, resulting in an increased water uptake – which may proceed to form cataracts via complex biochemical mechanisms.

• Pharmaceutical drugs: You may be quite surprised to know that certain drugs may be the cause of cataracts; these include corticosteroids (asthma, and many immune conditions like allergies, eczema, etc), various gout medications, phenothiazines (for certain psychiatric disorders) amiodorone (for treatment of heart ailments like irregular heart beating). And Ezetrol (ezetimibe – used to lower cholesterol) has also been implicated.

• Environmental toxins: environmental exposure to heavy metals may contribute to cataract formation. Cadmium, copper, lead, iron, and nickel have all been found in lenses which have developed cataracts. A high level of cadmium in the lens is associated with smoking and can contribute to accumulation of other heavy metals.

Eric

DISCLAIMER: GrownUps is not a Health Professional and we are not making a recommendation to you. GrownUps accepts no responsibility for decisions made as a result of using the information provided by the author.