Xerophthalmia is a medical condition in which the eye fails to produce tears. It may be caused by a deficiency in vitamin A and is sometimes used to describe that lack, although there may be other causes. Xerophthalmia caused by a severe vitamin A deficiency is described by pathologic dryness of the conjunctiva and cornea. The conjunctiva becomes dry, thick and wrinkled. If untreated, it can lead to corneal ulceration and ultimately to blindness as a result of corneal damage. Xerophthalmia is a term that usually implies a destructive dryness of the conjunctival epithelium due to dietary vitamin A deficiency or a rare condition in developed countries, but still causing much damage in developing countries. Other forms of dry eye are associated with aging, poor lid closure, scarring from previous injury, or autoimmune diseases such as rheumatoid arthritis and Sjögren's syndrome, and these can all cause chronic conjunctivitis. Persistent dryness, scratchiness, red eyes and a burning sensation are common symptoms of dry eyes. These symptoms alone may prompt your eye doctor to diagnose dry eye syndrome. Dry eyes can become red and irritated, causing a feeling of scratchiness. Another symptom of dry eyes is a "foreign body sensation," which is a feeling that something is in your eye. And it may seem odd, but dry eye syndrome also can cause watery eyes. This is because dryness on the eye's surface sometimes will overstimulate production of the watery component of your tears as a protective mechanism. Dry eye symptoms may include any of the following: stinging or burning of the eye, a sandy or gritty feeling as if something is in the eye, episodes of excess tears following very dry eye periods, a stringy discharge from the eye, pain and redness of the eye, episodes of blurred vision, heavy eyelids, inability to cry when emotionally stressed, uncomfortable contact lenses, decreased tolerance of reading, working on the computer, or any activity that requires sustained visual attention, eye fatigue.
Xerophthalmia usually affects children under nine years old and "accounts for 20,000-100,000 new cases of childhood blindness each year in the developing countries". The disease is largely found in developing countries like many of those in Africa and Southern Asia. The condition is not congenital and develops over the course of a few months as the lacrimal glands fail to produce tears. Other conditions involved in the progression already stated include the appearance of Bitot's spots, which are clumps of keratin debris that build up inside the conjunctiva and night blindness, which precedes corneal ulceration and total blindness. Treatment can occur in two ways: treating symptoms and treating the deficiency. Treatment of symptoms usually includes use of artificial tears in the form of eye drops, increasing the humidity of the environment with humidifiers, and wearing wrap around glasses when outdoors. Treatment of the deficiency can be accomplished with a Vitamin A or multivitamin supplement or by eating foods rich in Vitamin A. Treatment with supplements and/or diet can be successful until the disease progresses as far as corneal ulceration, at which point only an extreme surgery can offer a chance of returning sight. There is no cure for dry eye syndrome and some people have recurring episodes for the rest of their lives, but there are treatments to help control the symptoms. The exact treatment for dry eye syndrome depends on whether symptoms are caused by the decreased production of tears, tears that evaporate too quickly, or an underlying condition.
The first thing to consider is whether there are any obvious factors that could be changed, such as altering any medication that is causing symptoms. If your dry eye syndrome is caused by an underlying medical condition, your GP will prescribe treatment for it or will refer you to an appropriate specialist. You may also be able to help prevent dry eye syndrome or ease your symptoms by adjusting your environment, keeping your eyes clean and improving your diet. Read more about self-treating and preventing dry eye syndrome. The other treatment methods are Lubricant treatments: Preservative-free drops, 'Oily' tear eye drops, Eye ointments. Anti-inflammatory treatments: Anti-inflammatory treatments, Corticosteroid eye drops and ointments, Oral tetracyclines, Ciclosporin eye drops. Surgery: Punctal occlusion, Salivary gland auto transplantation. Radioiodine therapy can also induce xerophthalmia, often transiently, although in some patients late onset or persistent xerophthalmia has been observed. The damage to the cornea in vitamin A associated xerophthalmia is quite different from damage to the retina at the back of the globe, a type of damage which can also be due to lack of vitamin A, but which is caused by lack of other forms of vitamin A which work in the visual system. Xerophthalmia from hypovitaminosis. A is specifically due to lack of the hormone-like vitamin A metabolite retinoic acid, since (along with certain growth-stunting effects) the condition can be reversed in vitamin A deficient rats by retinoic acid supplementation (however the retinal damage continues). Since retinoic acid cannot be reduced to retinal or retinol, these effects on the cornea must be specific to retinoic acid. This is in keeping with retinoic acid's known requirement for good health in epithelial cells, such as those in the cornea.