|Year : 1981 | Volume
| Issue : 4 | Page : 495-497
Nutrition and eye
P Siva Reddy
Institute of ophthalmology and Sarojini Devi Eye Hospital, Hyderabad, India
P Siva Reddy
Institute of ophthalmology and Sarojini Devi Eye Hospital, Hyderabad
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Reddy P S. Nutrition and eye. Indian J Ophthalmol 1981;29:495-7
At the outset, let me wish all the delegates a happy new year. I thank the scientific committee of our organization for giving me the opportuniy to be the convenor of this very important symposium on "Nutrition and Eye". I have tried my best to make it exhaustive, interesting, and useful. I may be excused, if I have not-included some of the papers sent by some delegates.
I must congratulate all the speakers for preparing such excellent papers; which are of a high order. I must bring to the notice of our delegates that among our speakers, there are three non-ophthalmic scientists from the National Institute of Nutrition, Hyderabad, who were kind enough to readily agree to participate, and present their original research papers. 1 must specially thank Dr. Srikantiah, Director of National Institute of Nutrition, Hyderabad and Dr. Vinodini Reddy of the same institute who has done extensive research in vitamin A and blindness and published several articles in national and international journals. She has earned several laurels for her work.
In a developing country like India, malnutrition continues to be a serious public health problem and affects not only the health and well-being of large segments of population, but also national development. It is often said that malnutrition is a by-product of poverty, ignorance and underdevelopment.
A multitude of conditions and diseases can lead to visual impairment and to its extreme manifestations in the form of blindness, of these, malnutrition is the most important cause of preventable blindness, especially in young children. It is a serious public health problem in many developing countries.
Serveral nutrients like protein, vitamin A, and B-complex vitamins are required for the normal function of the eye. But it is the deficiency of vitamin A that affects the eye most. Mild deficiency produces changes in the conjunctival epithelium but more severe deficiency leads to keratomalacia and loss of vision. The incidence is particularly high in preschool children and is frequently associated with protein calrie malnutrition. It is difficult to estimate how many children in India are becoming blind due to malnutrition but the figure suggested is 10,000 per year. This is probably an underestimate. According to the ICMR surveys (1974), vitamin A deficiency contributes to about 20% of all cases of blindness in the country.
Assessment of the problem
Information on prevalence of xerophthalmia is obtained from field surveys as well as hospital records. Although these are important sources of information, one must be aware of their limitations. In areas where medical services are indaquate, the problem may be underestimated or even go undetected.
According to Mclaren, the impairment of adaptation resulting in night blindness is almost the first symptom of vitamin A depletion syndrome.
In India, results of several field surveys have shown that about 5-10% of children exhibit ocular signs of vitamin A deficiency, mostly conjunctival lesions. The incidence of corneal lesions is less than 1%. Keratomalacia is the final stage of xrophthalmia and is often associated with severe protein calorie malnutrition and infection. Though several cases are seen in the hospitals, community surveys show relatively low incidence rate. One of the reason is that such children are usually sick and easily missed in a community survey. Chances of survival are also low in such cases. This has been confirmed by a recent study carried out in Hyderabad, wherein children admitted to the hospital with corneal lesions were followed up. 10% of them died within a few days after admission. Of the surviving children, those who were treated for corneal lesions showed no residual evidence of vitamin A deficiency, while those who had keratomalacia showed eye sequele with partial or total blindness. The follow-up study showed that 30% of the blind children had died within 6 months after discharge. High mortality of children with keratomalacia has been reported from other countries as well. These results thus show that in community surveys, the problem of blindness due to vitamin A deficiency is underestimated not only because of high mortality but also due to difficulties in determining the exact cause of eye sequele in the surveying child.
Prevention and control
What are the possibilities for prevention of blindness due to keratomalacia
The best and most rational way to improve the vitamin A status of a population is by changing its dietary pattern. Changing the dietary pattern of a population is a long range affair which is brought with difficulties and is limited by econmical constraint.
To improve vitamin A status more rapidly one may resort to a short cut-fortification of foods with Vit. A.
Other approach which is implemented all over the country is the method developed by the National Institute of Nutrition of Hyderabad i.e. periodic (every six months) administration of two lakhs vitamin A by mouth to children at risk.
Administration of a massive dose of vitamin A is one of the practical measures suggested to reduce the incidence of Xerosis This is, however, a temporary measure and provides only a partial solution. In the long run, the problem of vitamin A deficiency can be solved only by raising the socio-economic levels of the population.
The physician who is treating cases of Xerophthalmia is usually subjected to a wide range of emotional feelings. On the one hand he may feel gratified with the dramatic response of early corneal xerosis. But on the other occasions, which are disconcertingly numerous, when children come in advanced stages of keratomalacia he sees that all is already lost. Even large doses of vitamin A cannot restore the vision. To prevent this tragic situation we should take up the challenge of preventing vitamin A deficiency in our population.
Inadequate intake of vitamin A is the most important cause of this disease in children and therefore the most rational approach to prevent this condition would be to improve their diets so as to ensure adequate intake of the vitamin. Foods containing preformed vitamin A are expensive but cheap sources of its precursor, Bata-carotene are easily available. Green leafy vegetables and fruits like papayya are rich in carotene. By encouraging the consumtion of these foods among the people, the incidence of xerophthalmia can be reduced considerably. This involves an intensive programme of nutrition education.
Additional measures like periodic administration of massive dose of vitamin A and fortification of foods with the vitamin have been suggested for the prevention of xerophthalmia. Massive dose programme has been in operation in India for the last 7 years. Preschool children are being given 200,000 i.u. of vitamin A twice a year and the coverage during last year was about 24 millions. Controlled studies carried out in Hyderabad have shown that it is effective in reducing the incidence of xerophthalmia. However, several problems are encountered in the implementation of this programme on a national scale.
Vitamin A deficiency is a multifaceted problem and those suffering from it not only need vitamin A but also general improvement in their diet and environment. The programme for the prevention of nutritional blindness should not be run in isolation but should be integrated with other health programmes.
Apart from vitamin A other ocular tissues which are affected by the nutrition deficiency are
- Malnutrition is a great problem for the corneal surgeon in India. Keratoplasty in our circumstances cannot be postponed to a later date specially in children and transplants have to be done at a much younger age than is usually considered safe.
- The role of vitamin A and protein in causation and healing of the corneal ulcer is a complex one.
- It is common to see angular conjunctivitis and blepharo-conjunctivitis associated with Riboflovine deficiency; corneal vascularisation superficial keratitis is also seen in ariboflavinosis.
- Certain refractive changes in malnourished children are observed. Significant myopia is seen in mal-nourished children. Improvement in diet brought them towards emmetropia.
One of the general objectives of the international year of the child is to provide basic health and nutrition services to all children. It is not possible to achieve this in one year but calls for continued action during the next decade. In accordance with these objectives, the government has already launched a series of action programmes. On this occasion, let us rededicate ourselves to continued services to combat malnutrition and blindness.