Why smoking increases the risk of sight loss

Smoking casues site lossThe relationship between smoking and sight loss is as strong as the link between smoking and lung cancer, say charity Eye Health UK.  These findings were part of a campaign that took place during No Smoking Week, designed to highlight the risks smokers face.

They estimated that smokers are four times more likely to lose their sight compared with non-smokers. Smoking damages the eyes causing conditions like age-related macular degeneration (AMD), cataracts, glaucoma and dry eye syndrome develop.

The links between smoking and heart and lung diseases are well known but many of the UK’s seven million smokers are unaware of how their habit damages their sight. Eye Health UK reports that fewer than 10% of smokers are aware that their eye health is at risk, but in comparison 92% know of the link between smoking and lung cancer.

How smoking damages sight

The cocktail of chemicals in tobacco smoke – arsenic, formaldehyde and ammonia – lead to oxidative stress. This increases oxidants in the eye which narrows blood vessels and damages the structure of the macula.

Narrowed blood vessels can cause both diabetic retinopathy and wet AMD. In the case of wet AMD, inadequate oxygen supply to the blood vessels as a result of smoking causes them to become damaged and leak fluid or blood into the macula. This type of AMD can be caused by smoking, is harder to treat and accounts for 90% of severe vision loss from the condition.

The tar in cigarette smoke also contributes to dry AMD, which is the more common form of the condition. The tar triggers the formation of fatty ‘drusen deposits  in the retina, which leads to sight impairment and loss if not treated.

Cigarette smoke also causes problems externally, with smokers being twice as likely to suffer dry eye syndrome. The smoke irritates the eyes leading to dry and itchy eyes often accompanied by damaged blood vessels. Dry eye syndrome can be caused by passive smoking too.

Smoking can also be linked to other eye conditions – it is estimated that heavy smokers (15 or more cigarettes per day) are three times more likely to develop cataracts. Smoking also causes high blood pressure and diabetes both of which are risk factors for glaucoma.

The biggest modifiable risk factor

Smoking has a drastic impact on the body, but the message is simple – quit.

Smoking is the single biggest modifiable risk factor for many common eye diseases, as well as cardiovascular disease and lung cancer, but quitting at any age will improve eye health.

Whether a patient is a light or heavy smoker, supporting them to quit will improve their eye health. Just one decade of being smoke-free reduces your risk of sight loss to that of a non-smoker.

Encouraging patients to quit for eye health

As with any eye condition, the key is to raise awareness, as currently many patients are unaware of the risk smoking poses to their sight. Combine this with the limited knowledge of conditions like age-related macular degeneration, and the risk of sight loss is even higher.

How can you educate your patients about smoking and sight loss? There are a number of ways to raise awareness:

The link between smoking and lung cancer was only widely accepted as late as the 1960s, but now the risks are very well-known by both patients and professionals. Our awareness of the risks to eye health are lagging well behind by comparison, so it is now time to bridge that gap. Smoking is a modifiable risk factor and thousands risk going blind without proper education.

To learn more about smoking and AMD read our dedicated infographic.