Xerophthalmia or “dry eye” is a condition of the eye, where the eyes do not produce enough tear and eyes become dry. Xerophthalmia is derived from Greek word means dry eye ("xeros" means dry and "ophthalmos” means eye so xerophthalmia means dry eye). Xerophthalmia represents all the ocular manifestations of deficiency of vitamin A in man, from mildest form night blindness to gravest keratomalacia, which is an ocular emergency.

How common is xerophthalmia?

Xerophthalmia is the most common nutritional disorder that affects the eye. Xerophthalmia is a disease of developing countries and accounts for up to 100,000 new cases every year in developing countries and many of these new cases ultimately cause blindness. Xerophthalmia is commonly a disease of childhood and generally affects children between 1-3 years of age and mainly seen below 9 years of age. Xerophthalmia is related to weaning of children and the younger the child the serious is the problem and complications. Xerophthalmia is common in Africa and Southern Asia, but rare in most of the developed and industrial countries. Xerophthalmia may be associated with PEM (protein energy malnutrition) and can be fatal if associated with PEM among children between 1-3 years of age which commonly affects the poorest families.

What are the causes of xerophthalmia?

The cause of xerophthalmia is deficiency of vitamin A (it is the severest form of vitamin A deficiency), which may be due to low level of vitamin A in diet or may be due to associated causes of xerophthalmia such as faulty feeding practice, ignorance among parents and community, diarrhea (especially chronic diarrhea), infections such as measles.

Other causes of “dry eye” may be due to old age, inability to close eye lids properly, auto-immune disease, Sjogren' s syndrome, systemic lupous erythematosus, rheumatoid arthritis, scleroderma, sarcoidosis, amyloidosis, and hypothyroidism and scar from previous injury of cornea.

What are the symptoms of xerophthalmia?

Xerophthalmia means all the ocular manifestation of the vitamin A deficiency in man i.e. mildest night blindness, conjunctival xerosis, Bitot’s spot, corneal xerosis and gravest keratomalacia.

Night blindness:

This is the first sing of vitamin A deficiency, where the affected individual is unable to see in dim light or in the evening and night time due to impairement in “dark adaptation”. Condition may deteriorate if Vitamin A intake is not increased.

Conjunctival xerosis:

Conjunctiva becomes dry and non-wettable. The conjunctiva looks wrinkled and muddy instead of normal shiny and smooth texture. The symptom of conjunctival xerosis is described as “emerging like sand banks at receding tide”.

Bitot’s spot:

These are triangular, foamy, yellowish or pearl white spots which are seen on the either side of cornea. The Bitot’s spots may be bilateral. Presence of Bitot’s spot in children indicates vitamin A deficiency and in adults it may be due the sequel of disease in the childhood.

Corneal xerosis:

This is a serious form of vitamin A deficiency. If not treated appropriately with vitamin A, it may lead to keratomalacia. The cornea becomes dry (moist appearance of cornea disappear), dull and non wettable. Cornea can become opaque or can ulcerate. Once it ulcerates it may heal but can leave a scar behind.

Keratomalacia:

Keratomalacia is liquefaction of cornea and it is a grave medical emergency. The whole of cornea or a part of the cornea may become soft and eye may burst open. The process of bursting develops very rapidly and if the eye collapses, vision is lost. Corneal xerosis and keratomalacia are the leading causes of blindness in many developing and underdeveloped counties.

How xerophthalmia is treated?

Treatment of xerophthalmia is essentially treatment of vitamin A deficiency (in mild forms, except medical emergencies such as keratomalacia). Supplementation of vitamin A and increase dietary intake of vitamin A is the essential part of treatment of xerophthalmia. Administration of large dose of 200,000 IU (international unit) which is equivalent of 110 mgs of retinol palmitate on two successive days is the treatment of choice in xerophthalmia and cause reversal of symptoms of xerophthalmia. The dose of vitamin A should be half (100,000 IU or 55 mgs of retinol palmitate) for children between 6 months to 1 year of age.

Symptomatic treatment of xerophthalmia include application of artificial tears to lubricate the eye, use of humidifiers, wearing wrap-around glasses (when outside), avaoiding dry and dusty environment etc.

How to prevent xerophthalmia?

The WHO has formulated the plan for the prevention of xerophthalmia in three integrated stages (1) short-term, (2) medium term and (3) long term actions for different member countries.

Short term strategy:

The short term strategy to prevent xerophthalmia is to administer large doses of vitamin A in recommended doses periodically to vulnerable groups such as malnourished children. This is a very effective preventive approach and can be organized easily with available infrastructure.

Add table for recommended doses

Medium term strategy:

This is widely used method to prevent xerophthalmia. This is to ensure the adequate intake of vitamin A by fortification of food items such as addition of vitamin A in cooking oil, sugar tea, skimmed milk etc. But the problem is to choose a food item which is to be fortified with vitamin A that is consumed by most of the vulnerable group of people and the fortification may be costly.

Long term strategy:

The long term strategy to prevent xerophthalmia is aimed at reduction or if possible elimination of the factors which cause xerophthalmia or vitamin A deficiency. The long term strategy include educating the vulnerable groups and mothers to consume locally available and cheap food items liberally with good amount of vitamin A, such as dark green leafy vegetables; educate the mothers to breastfeed for as long as possible and inform about the advantages of breast feeding; ensure safe and adequate drinking water supply by improvement of environmental health and sanitation. Long term strategy also include immunization against infectious disease such as measles, better feeding of vulnerable children, improvement of health services and health education for mothers and children. In other words the long term strategy to prevent xerophthalmia includes improvement of comprehensive primary health care.

Related Articles/Sites/Sources:

1. WHO (1984) Strategies for the prevention of blindness in national programs, Geneva, WHO.