Signs and Symptoms of Dry Eye
Dry Eye is a condition that develops when the amount of tears produced is not sufficient to maintain the moisture balance in your eye. This can result in that scratchy sensation, a continuous feeling of dryness, stinging and a sensation of a foreign body in your eye. Ironically in an effort to fight off the condition, dry eyes can cause you to produce excessive tears, which is why some people experience watery eyes.
The main function of tears is to maintain the health of the corner of your eye by washing away foreign matter and ensuring that the surface of your eye remains moist, smooth and clear. Tears also rinse away dust particles from your eyes and contain enzymes that protect your eyes from bacteria that can cause infections.
Hot, dry and/or windy climates, high altitudes, excessive sun exposure, central heating, air conditioning, hair dryers, cigarette smoke, air pollution, air travel.
Allergy medications, esp. antihistamines, Antidepressants,(e.g. amitriptyline, diazepam), Some blood pressure medications, parkinson's medications, birth control pills, diuretics, beta blockers, sleeping pills, many pain medications, certain medications which regulate heart rhythm irregularities, decongestants
Two million individuals abandon soft contact lens wear altogether each year with nearly 50% of these contact lens "dropouts" attributing dryness or discomfort as the primary reason.
Parkinson's disease, Sjögren's syndrome (an auto-immune disease), Rheumatoid arthritis, Lupus, Lacrimal gland deficiency, Diabetes, Sarcoidosis, Stevens-Johnson syndrome, Rosacea: Facial rosacea is commonly associated with ocular rosacea, which causes conditions such as blepharitis.
Dry eye is the most common complaint or adverse event following LASIK.
Thyroid conditions, Hormonal changes during menopause, Decreased production of androgen, Estrogen supplementation -(there are reports both of this improving dry eye conditions and worsening them).
Blinking is critical in spreading tears over the surface of the eye and stimulating tear production. A chronic low blink rate is associated with dry eye symptoms. Computer use, reading, and watching TV are the three activities most commonly associated with a low blink rate.
Causes of Dry Eye Disease
Dry eyes can occur naturally as a result of aging or hormonal changes, typically in women who are pregnant, taking oral contraceptives or going through menopause. In fact, women over 50 have a 50% greater risk of dry eye disease than men do of the same age. It can also result from taking certain medications that reduce tear production such as antihistamines, blood pressure medications, and antidepressants.
Environmental factors can also play a role in drying out the eyes and DED is common in areas where the climate is dry, dusty and windy. Home air conditioners or heating systems and excessive time spent staring at a computer or television screen can also dry out eyes and exacerbate symptoms due to the lack of blinking while staring at our screens.
Individuals that suffer from certain medical conditions such as diabetes, blepharitis, lupus, arthritis, and thyroid problems are more vulnerable to developing DED. Other causes can be due to eye surgery including LASIK, certain conditions in which the eyelids don’t close properly or extended contact lens use.
Diagnosis of Dry Eye Disease
Typically, dry eye disease can be diagnosed through a comprehensive eye exam and a description of your symptoms. On some occasions, the eye doctor might decide to do a test that measures how quickly your tears evaporate from the surface of your eye. By instilling a simple dye called fluorescein (much like food coloring) the doctor is able to watch and count how long it takes the tears to start to break up after they’ve asked you to hold your eyes open after a blink.
This is called TBUT or a Tear Break Up Time test. A low TBUT generally indicates a lipid (aka oil) deficiency in the tears resulting from oil glands in the eyelids not functioning properly.
In another type of test, called a Schirmer test, a strip of filter paper is placed under the lid of the eye and you will be asked to close your eye for five minutes. Following the test, the amount of moisture on the strip will be measured. Schirmer tests are performed less frequently than a TBUT test.