Dry eye syndrome Home A-Z Health Information Health Library A-Z Dry Eye Syndrome Overview Dry eye syndrome refers to a condition resulting from the eyes being unable to produce enough tears or the tears evaporating too quickly. This causes the eyes to dry out and eventually become inflamed. The incidence of dry eye syndrome increases with ageing, especially in women. Around 33% of people aged > 65 years may have this condition. Dry eye syndrome is common in patients with blepharitis and/or connective tissue disorders and among contact lens users.Tears are important as the tear film (the layer formed by tears at the front of the eye) not only lubricates the eyes, keeping them moist, but also plays a role in focusing the light into the eye.The tear film comprises three layers, each with different functions:The mucin layer (closest to the eye): It coats the cornea (the dome-shaped clear front layer of the eye), forming a foundation for the other layers.The aqueous layer (middle layer): It is mainly made of water and is the layer that is most associated with ‘tears.’ It is produced by the lacrimal (tear) gland and nourishes the cornea, providing it with oxygen, moisture, and other important nutrients.The lipid layer (outer layer): This is an oily film that seals the tear film, preventing the evaporation of the aqueous layer.The mucin and lipid layers are produced by small glands around the eye. When we blink, the tears are evenly spread over the front of the eye. The puncta (tiny drainage holes on the inside of the eyelids) drain away the excess tears, channelling them into the nose. This phenomenon explains why people often experiencing a runny nose while crying. Causes Several causes of dry eye syndrome have been identified:Occurs mostly as a consequence of the natural ageing process.Blinking problems.Problems with tear gland function, such as meibomian gland dysfunction.Some drugs, such as antihistamines and oral contraceptives, can cause dry eye.Using contact lenses may exacerbate (worsen) dry eye.Sometimes, dry eye represents a symptom of conditions affecting other body parts (particularly, Sjogren's syndrome or arthritis). Sjogren's syndrome is a chronic autoimmune condition marked by a dry mouth and dry vagina (apart from dry eyes). This condition may also be associated with certain types of arthritis. Symptoms Eye irritation, including itchiness, dryness, and discomfort in the eyes.Redness and a burning, stinging, or gritty sensation in the eyes.Temporary episodes of blurry vision, which normally go away with blinking or after a short time period.Sometimes, excessive watering from the eyes.Often, the eyes do not feel dry, but there are no tears during crying or when peeling onions. Diagnosis No single test that can diagnose dry eye has been established. However, ophthalmologists may perform certain procedures to diagnose this condition:Comprehensive eye examinations: Eye examinations that include a comprehensive assessment of the overall ocular and general health are performed.Schirmer tear test to measure the tear volume: Blotting paper strips are placed under the lower eyelids for five minutes to measure the extent to which the strips are soaked by the tears. The tear volume may also be measured via the phenol red thread test. In this test, a thread filled with phenol red (a pH-sensitive dye that changes colour upon contact with tears) is placed over the lower eyelid. After the thread is wetted by tears for about 15 seconds, the tear volume is measured.Staining tests to determine the tear quality: Eye drops containing special dyes are administered to determine the surface condition of your eyes. Corneal staining patterns are then examined, and the time required for the tears to evaporate is measured.Tear osmolarity test: The tear composition (levels of water and particles in tears) is measured. Reduced levels of water in the eyes are indicative of dry eye disease.Assessment of markers: The levels of dry eye disease-specific markers (such as decreased lactoferrin levels or elevated matrix metalloproteinase-9 levels) are measured. Treatment Artificial tears/tear substitutes: Over-the-counter artificial tears are often helpful in treating mild or moderate-stage dry eye syndrome. However, for patients with severe dry eye disease who need to use eye drops frequently (more than 6 times a day) or for patients who are contact lens users, preservative-free eye drops are recommended.Eye ointments can help lubricate the eyes. However, these are best used at night as they often cause blurred vision.Using the LipiFlow device (an FDA-approved procedure for Meibomian gland dysfunction).Lacrimal punctal plugs may be required to treat severe cases of dry eye syndrome.