Dry eye is a condition characterized by the lack of adequate lubrication for the eyes. Tears play an important role in lubricating and nourishing the outer surface (cornea) of the eye. Tears are composed of water, fatty oils and mucus that keep the eye surface smooth and clear, wash away foreign matter, as well as prevent infection. Affected quality and quantity of the tears may lead to dry eyes.
The symptoms of dry eye can be seen in both eyes and may include red eyes, burning and irritation of eyes, eye fatigue, and sensitivity of eye to light. Patients with dry eye may face difficulty in wearing contact lenses and may have blurred vision.
The common causes responsible for the development of dry eye are:
- Poor quality of tears influenced by the composition of oil, water, and mucus in tears
- Insufficient tear production after age 50, in postmenopausal woman, in association with medical conditions (rheumatoid arthritis, diabetes, thyroid disorders and vitamin A deficiency), laser eye surgery and damage of tear gland
- Less blinking of the eyelid, as blinking helps in spreading of the tears
- Certain medications such as hypertensive drugs, antihistamines, hormone replacement therapy and antidepressants
- Other causes include exposure to dry wind or continuous working on computer or reading for long time without blinking
Usually dry eye does not produce any serious complications, but it can sometimes lead to increased risk of eye infection, eye inflammation, corneal scarring and vision problems.
Diagnosis of dry eye involves review of medical history and physical examination of the eyes. Tears volume (Schirmer test) and tears composition (using special dyes) are determined. Strips of blotting paper are placed under your lower lid for five minutes, and measured for the extent to which they are soaked by your tears. A special dye may be instilled into your eyes to view the flow of tears and other surface changes due to dryness. In addition, your eyelid and cornea can be evaluated by using bright light and magnification.
The basic approach of treating dry eye is to manage quality and quantity of tears by conserving tears, using artificial tears and increasing tear production. Your doctor may help conserve your tears by surgically blocking the tear ducts with tiny silicone plugs to reduce tear loss. It is a permanent procedure that is recommended when tear loss in the eyes is very frequent. In some cases, your eyes can be covered with special contact lenses that prevent the loss of moisture. The artificial tears approach includes the use of eye drops or ointments to retain the moisture of the eyes.
Some of the basic instructions to reduce symptoms of dry eyes include:
- Blink frequently
- Maintain adequate humidity in the air at home or workplace
- Wear sunglasses to prevent direct exposure to sun and dry wind
- Take nutritional supplements rich in essential fatty acids
- Drink plenty of water daily