Dry eye is a condition that occurs when tears cannot properly lubricate the eyes. This is caused by either a decrease in tear creation or an increase in tear evaporation. If not treated, dry eye can cause lasting damage to the corneal surface and declining vision.
Esen Akpek, M.D., director of the Ocular Surface Disease and Dry Eye Clinic at the Wilmer Eye Institute discusses the causes, symptoms and treatment options for this common condition.
What causes dry eye?
Several factors can cause dry eye.
Evaporation of water from the tear film can increase due to blepharitis/meibomian gland dysfunction. “Blepharitis/meibomian gland dysfunction causes decreased production or altered composition of oil and is a common condition associated with rosacea, Demodex mites, graft versus host disease and other conditions,” says Akpek.
Decreased tear production is often associated with an autoimmune or inflammatory systemic condition such as Sjögren’s, sarcoidosis, lupus or rheumatoid arthritis, which can damage the tear glands. “Pain sensation, such as dryness or discomfort, is part of the creation of tears, so eyes with decreased sensation will tear less,” says Akpek. “In addition, since normal pain sensation is necessary for corneal surface cell regeneration, the loss of that sensation is detrimental to the health of the cornea.”
Decreased corneal sensation can be caused by:
- Chronic dry eye
- Long-term contact lens wear
- Viral infections such as shingles
Sjögren’s is one of the most common causes of tear gland damage. This is a chronic inflammatory disease in which mucous membranes, especially those in the eyes and the mouth, become extremely dry. Patients with Sjogren’s syndrome are at risk for developing internal organ involvement such as hepatitis, interstitial lung disease, nephritis, vasculitis or lymphoma.
Dry Eye Symptoms
Dry eye can result in symptoms including:
- A sandy or burning sensation on the eye surface
- Other eye discomfort
- Blurred vision
- Eye redness that progresses through the day
Dry Eye Diagnosis
Dry eye syndrome can be diagnosed by the following methods.
- A routine eye exam by an eye doctor or specialist
- The Schirmer’s test, during which the volume of tears produced is measured with a slip of paper placed under each eye to absorb the water released for five minutes.
- Tear film breakup time — A test that uses dyes on the ocular surface to observe the tear film breakup time
- A fluorescein dye test, which uses an orange dye and a blue light to observe microabrasions of the tissue covering the front of the corneal epithelium
- A tear film osmolarity test, which determines the amount of solutes in tear film versus solvent (water) — this is known as tear composition
- Blood tests and other work-ups that are ordered in some cases to uncover an underlying rheumatological disorder
Dry Eye Treatment
Treatment for dry eye syndrome depends largely on the severity of the disease.
Mild cases of dry eye syndrome require no more than use of artificial tear solutions and hot compresses, with eyelid massage using ophthalmic ointments.
“If the condition is not sufficiently managed with artificial tears, you might use sustained-release eye lubricants,” says Akpek. An insert placed in the eye area slowly dissolves and thickens the tear film, Akpek explains. “Your doctor might also recommend prescription eyedrops,” she says.
You may also opt for scleral lenses, which are special contact lenses that trap moisture onto the eye’s surface.
- Punctal occlusion: During this painless procedure, small tear draining holes at the corner of the eye are blocked with tiny plugs in order to increase tears.
- Thermal pulsation: Specialized devices provide controlled heat energy to the eyelids and massage them from the inside-out and outside-in. The heat breaks down obstructions in the meibomian glands and improves oil secretion.
- Microblepharoexfoliation: A microsponge gently exfoliates away the biofilm — crusting, bacterial colonies and mites that can infest the eyelashes.
- Intense pulsed light: Nonlaser light energy is applied to the eyelid skin to break down obstructions in the meibomian glands, improve oil secretion, decrease eyelid redness and reduce spider veins.
- Meibomian gland probing: This procedure clears glands of obstructive scar tissue and hardened secretions.