الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 109 |  |  |
| | | from | 109 | | |
Abstract
Cataract is a clouding of the lens that leads to decreased vision. It increases with age and is one of the leading causes of blindness worldwide. The only treatment currently available is surgery. Cataract involves decreased vision and deteriorated quality of life resulting in socio-economic consequences. Elderly individuals with compromised vision require assistance. Furthermore, expenses increase due to a rise in operation volumes. Cataract operation costs billions of dollars each year with increasing rates due to aging of the population. Any intervention which could decrease cataract operation or delay it even for small level is recommended. Therefore, finding modifiable risk factors for cataract is of public health importance. Age-related cataract in Epidemiologic studies has shown that the etiology of cataract is multifactorial. Cigarette smoking, UV-exposure, diabetes and steroid medication have been associated with cataract in previous studies .Dietary patterns and vitamin supplement use was also of importance. Oxidative stress which is a condition of disrupted balance between oxidants and antioxidants to lens proteins and lipids is suggested to be involved in the development of cataract. Antioxidants may protect against oxidative damage
Age related cataract is considered to be the result of lifelong molecular damage by reactive oxygen species to lens proteins To counteract these potentially damaging stress factors, the lens has an elaborate antioxidant defense system including enzymes such as glutathione peroxidase, glutathione reductase, catalase and superoxide dismutase, and the antioxidant vitamins C, E and some carotenoids . These antioxidants cannot be synthesized by the body and must be obtained from dietary sources, mainly fruit and vegetables.
For many years, there has been interest in the question of whether diet could be used to help in cataract prevention. Many studies investigated the effect of single nutrient intake on the prevalence of age related cataract. Few studies examined the effect of food intake on age related cataract prevention.
Higher intake of vitamin C, E and lutein and zeaxanthin was associated with decreased cataract prevalence in many studies. Few studies have investigated the effect of antioxidant rich food like (fruit, vegetables, nuts and cereals) on the occurrence of age related cataract. The effect of trace minerals antioxidants like zinc and selenium has been investigated in few researches with no conclusive results.
On the In 2004, the WHO launched a strategy to reduce the prevalence of non-communicable diseases including cataract. One of the dietary recommendations is to eat 5 or more portions of fruit and/or vegetables a day. The current intake is less than this level
The study is an attempt to investigate the relationship between the intake of antioxidant rich foods and the occurrence of age related cataract.
The study is case control study and was conducted in Alexandria ophthalmology hospital. 301 subjects with cataract and 301 subjects without cataract have investigated about their intake of food rich in antioxidants and the level of antioxidants in diet has estimates using 24 hour dietary recall.
Summary
82
On analyzing results from this study, it was observed that the mean of vegetables group score was 30.5±9.7 among cataract patients and 43.3±11.8 among cataract free group. The mean of fruit group score was 16.1±6.4 among cataract patients and 21.9±8.6 among cataract free group. It also shows that the mean of bakery products group score was 17.5±6.04 among cataract patients and 32.3± 14.5among cataract free group. The mean of dairy products group score was 6.7±3.1 among cataract patients and 12.1±5.7 among cataract free group. The mean of meat group score was 9.8±3.4 among cataract patients and 20.0±8.9 among cataract free group. All scores of intake among cataract free subjects was significantly higher than cataract patients , as was found in most studies correlating food groups rich in antioxidants with cataract risk.
It was also observed that median intake of vitamin C among cataract free subjects (28.8 mg) was significantly higher than cataract patients (21.6 mg) thus supporting a strong evidence of protective role of vitamin C against cataract as was found in most studies.
The median intake of Lutein & Zeaxanthin among cataract patients was (120.7μg) and among the cataract free group was (128.5μg). The median intake of vitamin E among cataract free patients (0.9 mg) was slightly higher than among cataract patients (0.8 mg).
The median intake of selenium among cataract patients (52.73 μg) was higher than the cataract free group (51.59 μg).Among cataract patients, the median intake of zinc (5.8mg) was slightly higher than the cataract free group (5.7mg). There was no statistical significant difference between the two groups.
Other risk factors of cataract have been investigated like smoking, sunlight exposure and family history. Current smoking was higher among cataract free subjects which is not consistent with some studies.
The study reveals the following conclusions. The study support the important role of the antioxidant vitamins on cataract prevention as high intake of food rich in antioxidants was higher among subjects without cataract. High daily intakes of fruit, vegetables, cereals, meat, dairy products and beans were significantly associated with decreased prevalence of cataract. This study reinforces the WHO recommendations on the benefits of diets rich in fruit and vegetables. High daily intakes of vitamin C is significantly associated with decreased cataract risk. High daily dietary intake of lutein and zeanthein is associated with decreased cataract prevalence. Long duration of multivitamin supplement intake is associated with decreased cataract risk. Most of the study sample were lowly educated and had poor eating habits. High selenium and zinc intake is not associated with decreased cataract risk. Smoking cessation decreases the risk of age-related cataract. Age is important risk factor for cataract.
from the present study the recommendations are:
- Daily intakes of 5 or more portions of fruit and vegetables on the risk of non-communicable diseases, including age related cataract are recommended.
- Establishment of a nutritional education program should be carried out for young people explaining the importance of eating healthy food rich in antioxidants and its benefits on prevention on diseases related to aging and cataract one of them.
Summary
83
- Health education programs to encourage people on smoking cessation and clarifying the health hazards of smoking.
Recommendations for further researches:
- Further understanding of both, the individual role of the antioxidants, and their synergistic effects is needed.
- Taking in consideration the effect of food processing and cooking on the amount of antioxidant in food.
- Studying the effect on modifying the diet to antioxidant rich diet on the progression of cataract in early stages.
- Concentration on studying on the antioxidant rich diet and its effect on aging and chronic diseases rather than antioxidant supplements.
- Studies taking into account gene-environment interactions are also needed as genetics may influence how people respond to dietary antioxidants and physical activity.
- Future observational and experimental studies may consider examining the use of low-dose (close to RDA) multivitamins (or a combination of other low-dose antioxidants) for the prevention of cataract, in ―high-risk‖ populations, for example those with low antioxidant intake and that are at risk of developing or already have micronutrient deficiencies.
- It would be of interest in future studies to include information on type of cataract (nuclear, cortical and posterior subcapsular cataract).
- Assessing the effect of physical activity on the cataract prevention