Definition

Dry Eye Syndrome (also called dry eye disease, dysfunctional tear syndrome, and keratitis sicca) is a poorly functioning tear layer covering the cornea and conjunctiva, usually caused by inadequate quantity and/or quality of the tears.

Symptoms

Symptoms of dry eye syndrome are dryness, grittiness, burning sensation, blurred vision, fluctuating vision, redness, mucous discharge, contact lens intolerance and ironically, episodes of excess tearing. Many of these symptoms also can be caused by other ocular conditions, such as blepharitis (inflammation of the eyelids) and ocular allergies. Also, inflammation of the surface of the eye may occur along with the condition. If left untreated, this condition can lead to pain, ulcers, or scars on the cornea and some vision loss. However, permanent loss of vision from the condition is uncommon.

Causes

There are two primary causes of dry eye:

• Aqueous tear deficiency where there is an insufficient amount of tears produced to adequately lubricate the ocular surface; and
• Evaporative tear deficiency where the lipid layer of the tears (produced by the meibomian glands) is inadequate to prevent rapid tear evaporation. Most patients have a combination of both.
• Dry eye can be a temporary or chronic condition:
• It can be a side effect of some medications, including antihistamines, nasal decongestants, tranquilizers, certain blood pressure medicines, Parkinson’s drugs, birth control pills, and anti depressants.
• Skin disease on or around the eyelids can result in the condition.
• Diseases of the glands in the eyelids, such as meibomian gland dysfunction, can cause it.
• It can occur in women who are pregnant.
• Women who are on hormone replacement therapy may experience it. Women taking only estrogen are 70 percent more likely to experience the condition, whereas those taking estrogen and progesterone have a 30 percent increased risk of developing it.
• It can also develop after the refractive surgery known as LASIK. These symptoms generally last three to six months but may last longer in some cases.
• It can result from chemical or thermal burns scarring the membrane lining the eyelids and covering the eye.
• Allergies can be associated with it.
• Infrequent blinking, associated with staring at a computer or video screens, may also cause the condition.
• Both excessive and insufficient dosages of vitamins can contribute to dry eye.
• Homeopathic remedies may make the condition worse.
• Loss of sensation in the cornea from long-term contact lens wear can lead to the condition.
• 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 eye’s surface area increases, as in thyroid disease, when the eye protrudes forward or after cosmetic surgery, if the eyelids are opened too widely, dry eye can result.
• Dry eye may occur from exposure keratitis, in which the eyelids do not close completely during sleep.

Risk Factors

Increasing age, female gender, certain medications such as oral beta-blockers, anti-histamines, certain systemic conditions such as rheumatoid arthritis and Sjögren’s syndrome.

Complications

Filamentary keratopathy, corneal abrasions, corneal scarring, corneal ulceration, corneal perforation.

Tests and Diagnosis 

Slit lamp examination is essential. Other tests include Schirmer test, ocular surface staining with fluorescein or lissamine green, tear osmolarity testing, tear MMP-9 testing.

Treatment

Stepwise approach to treatment including tears with preservative, tears without preservatives, tear gels and ointments, cyclosporine drops, punctal plugs, short course of steroid drops, Lacriserts. More aggressive treatments include punctal occlusion with cautery, serum tears, scleral contact lens such as the PROSE lens, small lateral tarsorrhaphy (closure of the eyelids). Treat blepharitis if present.

Support

Sjögren’s Syndrome Foundation

Prevention

Treating patients when they have early signs or symptoms is the best way to prevent progression of the disease and permanent visual complications.