Prevention of cataract

Regular eye exams remain the key to early detection. If you're over age 65, schedule eye exams at least every other year. Although most cataracts occur with age and can't be avoided altogether, you can take steps to help slow or possibly prevent the development of cataracts:

Don't smoke. Smoking produces free radicals, increasing your risk of cataracts.

How free radicals increases your risk of cataracts?
Oxygen, an element indispensable for life can, under certain situations, have severely deleterious effects on the human body. Most of the potentially harmful effects of oxygen are due to the formation and activity of a number of chemical compounds, known as reactive oxygen species, which have a tendency to donate oxygen to other substances. Many such reactive species are free radicals and have a surplus of one or more free-floating electrons rather than having matched pairs and are, therefore, unstable and highly reactive. Types of free radicals include the hydroxyl radical (OH.), the superoxide radical (O.2), the nitric oxide radical (NO.) and the lipid peroxyl radical (LOO.).

Production of free radicals in the human body

Free radicals and other reactive oxygen species are derived either from normal essential metabolic processes in the human body or from external sources such as exposure to X-rays, ozone, cigarette smoking, air pollutants and industrial chemicals.

Free radical formation occurs continuously in the cells as a consequence of both enzymatic and non-enzymatic reactions (Figure 1). Enzymatic reactions which
serve as sources of free radicals include those involved in the respiratory chain, in phagocytosis, in prostaglandin synthesis and in the cytochrome P450 system. Free radicals also arise in non-enzymatic reactions of oxygen with organic compounds as well as those initiated by ionizing radiations. Some internally generated sources of free radicals are [1]:

mitochondria
phagocytes
xanthine oxidase
reactions involving iron and other transition metals
arachidonate pathways
peroxisomes
exercise
inflammation
ischaemia/reperfusion.
Some externally generated sources of free radicals are [1]:

cigarette smoke
environmental pollutants
radiation
ultraviolet light
certain drugs, pesticides, anaesthetics and industrial solvents
ozone.

With electrons unhinged, free radicals roam the body, wreaking havoc. The free radical, in an effort to achieve stability, attacks nearby molecules to obtain another electron and, in doing so, damages those molecules. This situation can be compared to letting a bachelor into a dance where people have come as couples. The bachelor begins cutting in, each time leaving another bachelor, so the breaking up of couples spreads through the dance floor.

If free radicals are not inactivated, their chemical reactivity can damage all cellular macromolecules including proteins, carbohydrates, lipids and nucleic acids. Their destructive effects on proteins may play a role in the causation of cataracts. Free radical damage to DNA is also implicated in the causation of cancer and its effect on LDL cholesterol is very likely responsible for heart disease. In fact, the theory associating free radicals with the aging process has also gained widespread acceptance



Eat a balanced diet. Include plenty of fruits and vegetables in your diet. Eating lots of fruits and vegetables may have a modest effect in preventing cataract development, though this hasn't been definitively proved.
In one study, lead scientist Paul Jacques, DSc, director of the Nutritional Epidemiology Program at the Center, and his colleagues analyzed the diets and examined the eyes of a group of Boston-area women over the course of five years. Among the study participants, who were all members of the larger Nurses' Health Study, women who reported supplementing their diets with vitamin E (a powerful antioxidant) for 10 years or more had significantly less progression of cataract development at the five-year follow-up exam. A similar relative decrease in cataract progression was seen in women who reported higher intakes of two of the B vitamins, riboflavin and thiamin, when compared to women with lower intakes.
There is considerable interest in the role of antioxidant vitamins in the development of cataracts. Antioxidants neutralize the action of free radicals, thereby preventing damage to cells, and may be relevant to cataracts if oxidative damage to the lens is found to lead to cataract formation. Antioxidants are found naturally in food and include vitamin C (ascorbic acid), vitamin E (alpha-tocopherol), carotenoids, and anthocyanidins.

Protect yourself from the sun. Ultraviolet light may contribute to the development of cataracts. Whenever possible, wear sunglasses that block ultraviolet B (UVB) rays when you're outdoors.

Take care of other health problems. Follow your treatment plan if you have diabetes or other medical conditions. If you have a chronic illness, it's especially important that you take other preventive steps, such as wearing UVB-blocking sunglasses when outdoors and not smoking.

Researchers are continuing to explore new ways to prevent and treat cataracts, such as developing medications that would reduce or eliminate the need for surgery. But, until such a treatment exists, your chances of fully restoring your vision with cataract surgery are excellent if you have no other eye diseases.