What is dry eye?
Dry eye occurs when the eye does not produce tears properly, or when the tears are not of the correct consistency and evaporate too quickly. In addition, inflammation of the surface of the eye may occur along with dry eye. If left untreated, this condition can lead to pain, ulcers, or scars on the cornea, and some loss of vision. However, permanent loss of vision from dry eye is uncommon. Dry eye can make it more difficult to perform some activities, such as using a computer or reading for an extended period of time, and it can decrease tolerance for dry environments, such as the air inside an airplane.
Other names for dry eye include dry eye syndrome, keratoconjunctivitis sicca (KCS), dysfunctional tear syndrome, lacrimal keratoconjunctivitis, evaporative tear deficiency, aqueous tear deficiency, and LASIK-induced neurotrophic epitheliopathy (LNE).
What are the types of dry eye?
- Aqueous tear-deficient dry eye is a disorder in which the lacrimal glands fail to produce enough of the watery component of tears to maintain a healthy eye surface.
- Evaporative dry eye may result from inflammation of the meibomian glands, also located in the eyelids. These glands make the lipid or oily part of tears that slows evaporation and keeps the tears stable.
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.
Causes and Risk Factors
- Dry eye can be a side effect of some medications, including antihistamines, nasal decongestants, tranquilizers, certain blood pressure medicines, Parkinson's medications, birth control pills and anti-depressants.
- Skin disease on or around the eyelids can result in dry eye.
- Diseases of the glands in the eyelids, such as meibomian gland dysfunction, can cause dry eye.
- Dry eye can also develop after the refractive surgery known as LASIK.
- Dry eye can result from chemical and thermal burns that scar the membrane lining the eyelids and covering the eye.
- Allergies can be associated with dry eye.
- Infrequent blinking, associated with staring at computer or video screens, may also lead to dry eye symptoms.
- Both excessive and insufficient dosages of vitamins can contribute to dry eye.
- Loss of sensation in the cornea from long-term contact lens wear can lead to dry eye.
- Dry eye can be associated with immune system disorders such as Sjögren's syndrome, lupus, and rheumatoid arthritis. Sjögren's leads to inflammation and dryness of the mouth, eyes, and other mucous membranes. It can also affect other organs, including the kidneys, lungs and blood vessels.
- Dry eye can be a symptom of chronic inflammation of the conjunctiva, the membrane lining the eyelid and covering the front part of the eye, or the lacrimal gland. Chronic conjunctivitis can be caused by certain eye diseases, infection, exposure to irritants such as chemical fumes and tobacco smoke, or drafts from air conditioning or heating.
- If the surface area of the eye is increased, as in thyroid disease when the eye protrudes forward or after cosmetic surgery if the eyelids are opened too widely, dry eye can result.
Depending on the causes of dry eye, various approaches can be used to relieve the symptoms. Dry eye is an ongoing condition. The first priority is to determine if a disease is the underlying cause of the dry eye (such as Sjögren's syndrome or lacrimal and meibomian gland dysfunction). If it is, then the underlying disease needs to be treated. Cyclosporine (Restasis), an anti-inflammatory medication, is the only prescription drug available to treat dry eye. It decreases corneal damage, increases basic tear production, and reduces symptoms of dry eye. It may take three to six months of twice-a-day dosages for the medication to work. In some cases of severe dry eye, short term use of corticosteroid eye drops or oral antibiotics that decrease inflammation is required. In some patients with dry eye, supplements or dietary sources (such as tuna fish) of omega-3 fatty acids (especially DHA and EPA) may decrease symptoms of irritation.
Another option is to plug the drainage holes, small circular openings at the inner corners of the eyelids where tears drain from the eye into the nose. Punctal plugs are inserted painlessly in the office setting. The patient usually does not feel them. These plugs are made of silicone or collagen, are reversible, and are a temporary measure. In severe cases, permanent plugs may be considered.
In some cases, a simple surgery, called punctal cautery, is recommended to permanently close the drainage holes. The procedure helps keep the limited volume of tears on the eye for a longer period of time.
What can I do to help myself?
- Avoid dry conditions and allow your eyes to rest when performing activities that require you to use your eyes for long periods of time.
- Use artificial tears, gels, gel inserts, and ointments as prescribed by your doctor.
- Avoid artificial tears with preservatives if you need to apply them more than four times a day or preparations with chemicals that cause blood vessels to constrict (usually states “Gets the RED out” on the bottle).
- A humidifier may help by adding moisture to the air.
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