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