Saturday, 23 July 2011

Eye Injuries from Smoking

Published in "Panorama"

Smoking can be injurious to the eyes

20% of people all over the world smoke! Which is to say that there are approximately 1.2 billion smokers in the world. About five trillion cigarettes were sold in 2003, 25% of which were bought by teenagers! Approximately 1 in every 10 adults, dies of smoking-related problems, worldwide. Smoking is a risk for over fifty diseases and it can kill a person in more than twenty ways. Passive smoking increases a person’s risk of health problems by a quarter. However, it is equally true that smoking is the biggest preventable cause of death. While it is a well known fact that smoking is implicated as a risk factor in many forms of cancer, cardiovascular and respiratory diseases and several other disorders, people are hardly aware that there is a very strong association between smoking and several common eye diseases, reveals Dr Shabbir Saifuddin, Specialist Ophthalmologist, Al Musallah Medical Centre and Jansons Medical Centre.

Recent research has proved that smoking is a contributory factor to both visual impairment and blindness. Hence, it is important to create an awareness among the public of this risk associated with smoking. Further, it is imperative for healthcare professionals to assist smokers from quitting the habit and help prevent smoking in the first instance, emphasizes the specialist.

Dr.Saifuddin throws light upon some of the eye disorders or problems that smoking can cause
Glaucoma: An animal study has shown a 5-mm Hg increase in eye pressure immediately after smoking.
Cataract: Smoking can cause direct and structural injury to the natural lens.
Age-related macular degeneration: Smoking may promote the formation of abnormal new blood vessels in the retina causing Macular degeneration.
Dysthyroid eye disease: Smoking can cause disturbances in the immune system, resulting in decrease control of immune cells against thyroidal antigens.

Tobacco contains nicotine which has a toxic or poisonous effect on the optic nerve which is the nerve of vision. Its continuous use or prolonged use, destroys the optic nerves, leading to blindness. This destruction may not always be complete but it nevertheless reduces the efficiency of the eye to a marked degree by paralyzing the nerves of the eyes.

The macula is the region of the retina with the finest blood supply in the body, serving the retinal receptors that enable us to see minute details clearly. Even before other body functions may be affected, there is obstruction and failure of the blood supply to the macula, thus causing gradual vision failure. New vessel growth and leakage can result in scarring of the retina and severe vision loss. The average age that people present with age-related macular degeneration in the first eye is around the age of sixty and it may take another five years for the second eye to become impaired. While there is no effective medical or surgical cure for the condition, rehabilitation measures enable people to live more independently. Smoking is a major factor contributing to the early development of age-related macular degeneration. When you inhale cigarette smoke thousands of chemicals get into your bloodstream and can travel throughout your body. These chemicals cause damage to the macula which is the most sensitive part of the retina, at the back of the eye. Tiny blood vessels can burst through the macula, leading to irreversible damage, or alternatively, the cells of the macula slowly die. Both ultimately lead to loss of vision.

The problem is that we breathe and soak up cigarette smoke and other toxic environmental pollutants. The cigarette smoke produces free radicals which are toxic to our eyes and to the rest of our bodies. They overwhelm our limited supply of antioxidants, especially if we aren't replenishing antioxidants by eating foods that contain them. When this happens, the free radicals are literally free to react with the cones in our macula, producing abnormal waste tips, which instead of getting naturally cleared, get accumulated in permanent deposits that gum up the macula.Smoking also enhances the generation of free-radicals and decreases the levels of antioxidants in the blood circulation and ocular tissue. Thus, the eyes are at risk of having free-radicals and oxidation attacks not only in active but passive smokers too, explains Dr.Saifuddin.

Almost every single one of the risk factors we have for macular degeneration can be linked to free radicals, explains Dr.Saifuddin. The older you are, the more exposure you've had to environmental toxins; hence aging enhances the risk factor. The lighter your eyes, the less protective is the pigment melanin which is supposed to protect you from free radicals produced by the sun. Dark green leafy vegetables are rich in the antioxidants that our eyes use to counteract free radicals. Hence, a diet low in these vegetables would make you more vulnerable. Smoking can be described as the activity of overloading your eyes with free radicals, since the chemicals in cigarettes are full of them. While at this stage there is no research to confirm at what point the damage occurs, however it is known that the process of macular degeneration is the result of progressive damage over many years. The condition is not usually detected until people are in their fifties or older, explains Dr.Saifuddin.

Are there any warning signals or signs for smokers or passive smokers to suspect their eyes are getting damaged? Yes. Eye specialists may be able to perform a simple test to indicate if one’s eyes are damaged and also the extent of the damage. You need to be seen urgently by the doctor if you suddenly become aware of distorted vision in one eye or if you notice a dark or grayish patch near the centre of your vision in one eye, emphasizes Dr.Saifuddin.

Is it possible then, to quit smoking and prevent the eye diseases and blindness? As far as eye is concerned, epidemiological studies of thousands of people have shown that the antioxidants are just the starting point for a preventive approach to eye health, reveals Dr.Saifuddin. “However, the single most important change one can make is to stop smoking. Smoking increases the risk of developing macular degeneration to a very significant extent and more than doubles this risk of cataracts. Other helpful lifestyle changes would include regular exercise. There is no cure for macular degeneration but not smoking or stopping smoking is one way to decrease the chances of developing this eye disease.”

Phytonutrients, micronutrients derived from plants, are the most under-rated sources of healthy nutrients for our body. Recent research has proved that dark green leafy vegetables contain nutrients which protect our sensitive retinal microcirculation, and help prevent and in some cases, even improve macular degeneration and retinopathy. Ginkgo biloba extracts has also shown to promote better circulation in the eye and brain, explains Dr.Saifuddin.

Can this damage be reversed with laser or other treatment? Dr.Saifuddin is emphatic, “No. Laser treatment can sometimes kill the new blood vessels before they hit the macula. However, most people are not able to be helped this way because the blood vessel has already involved the very centre of the macula and even after treatment, the condition recurs in half the cases and in almost all those who continue to smoke. A new treatment, photodynamic therapy (PDT) may be able to help some to reduce the severity of vision loss, but the majority of people with macular degeneration will still not be able to be treated.”


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