The Schirmer's test is a noninvasive eye exam used to assess the number of tears. Its aim is to establish if the tear glands produce enough fluid to keep the eyes healthy and moist. The tear test is mainly used to detect dry eye syndrome. It is an abnormality where the eyes lack enough lubrication or moisture because the tears glands can't produce sufficient tears.
As a consequence, the eyes are unable to wash out dust, dirt and other foreign material. The probability of developing the disorder increases with age and it is common among adults over 50 years old. Estimates indicate that over five million Americans in this age bracket suffer from the condition. The disorder causes redness, blurred vision, burning, and stinging in the eye. It is more common in women than in men.
The dry eye test has been in use for around 100 years. There are more modern and sophisticated methods of diagnosing dry eye, but the Schirmer's test is still useful in that respect.
Also Known As
- Tear test
- Tearing test
- Dry eye test
- Sjögren - Schirmer
- Basal secretion test
The Schirmer's test can be done at the doctor's office, eye clinic, or hospital by:
- A nurse
- A technician
- An optometrist
- An ophthalmologist
The doctor will order the test if he/she suspects that the tear glands are producing either too little or too many tears. It may be a situation where the patient has persistent symptoms (lasting longer than a week), such as:
- Eye fatigue
- Eye redness
- Blurred vision
- Pain in the eyes
- Sensitivity to light
- Chronic eye irritation
- Excessive dryness in the eye
- Challenges with night driving
- Difficulty wearing contact lenses
- A foreign body sensation in the eye
- Stringy mucus in or around the eyes
- Persistent watering or tearing of the eye
- A scratchy, burning or stinging sensation in the eyes
The Schirmer's test assesses the severity of the anomaly and confirms the dry eye. The test can also be used to help the doctor to detect Sjögren's syndrome. It is an autoimmune abnormality that causes a reduced function in the tear and salivary glands leading to dry eyes and mouth. In most cases, the test is used together with other examinations to confirm Sjögren's syndrome.
Some of the below factors may also cause dry eyes:
- Laser eye surgery
- Sjogren's syndrome
- Vitamin A deficiency
- Eyelid or facial surgery
- Changes in season or climate
- Lupus or rheumatoid arthritis
- Certain medications, such as antihistamines or decongestants
A watery eye may be due to:
- Pink eye
- The common cold
- Ingrown eyelashes
- Blocked tear ducts
- Irritation of the eye
- Complications from dry eyes
- Climate, unusually cold and windy weather
- Side effects of certain medications, including diuretics and sleeping pills
Preparation & Expectation
Preparation for the tear test is minimal and straightforward. The patient will need to remove the eyeglasses or contact lenses before the test. However, if the patient wears contact lenses, they should bring glasses because they can't wear the contact lenses for at least two hours after the test.
Before the test, the doctor may inquire from the patient about their tolerance to eye touch. If the patient is uncomfortable with the idea of something touching their eye, the doctor may numb them with anesthetic drops. The numbing drops may produce a stinging sensation which might make the patient mildly irritated or uncomfortable. The medication prevents the patient's eyes from watering during the procedure. The test can be done without applying numbing drops to diagnose other types of tear problems.
The procedure may vary. Frequently, once the medication has taken effect, the doctor will pull on the bottom of the patient's eyelid and insert a special strip of paper under the lid. He/she doctor will instruct the patient to close their eyes and to keep them closed for about five minutes (with the strip under the eyelid). During this period, the patient needs to avoid squeezing or touching their eyes because it may impact the results. Both eyes can be tested at the same time. After five minutes, the doctor will remove the strips from the eyelids and measure the quantity of moisture on each piece.
An abnormal test result will prompt the doctor to determine the underlying cause of the condition. Schirmer's test doesn't always effectively detect cases of dry eye. More tests may be required to establish a specific cause and the appropriate treatment.
The outcome of the test can be affected by the age of the patient. Older patients produce fewer tears. In general, for a person with healthy eyes, each strip should have over 10 millimeters of moisture.
- Abnormal results
An outcome of less than 10 mm indicates an abnormally low tear production while a reading of over 15 millimeters shows over production. If the outcome shows less than 5 millimeters of moisture the patient is considered to have severe dry eyes. Dry eye may be due to climatic/environmental changes or an underlying cause, such as:
- Vitamin A deficiency
- Previous facial or eyelid surgery
- Leukemia, a type of blood cancer
- Eye infections such as conjunctivitis
- Side effects of laser correction therapy
- Inflammation or swelling of the eyelids
- Sjögren's syndrome, an autoimmune disease
- Corneal anomalies, such as ulcers and infections
- Lymphoma, a cancer of the lymph system
Prescription eye drops are the conventional treatment for chronic dry eyes. The doctor may recommend over-the-counter drops if the patient's eyes are not severely dry. In other cases, additional treatment may be necessary to help treat and manage the condition.
Risks & Complications
Schirmer's test is a straightforward procedure without any complications or risks. However, the patient should avoid rubbing their eyes until the effects of the medication wear off in about 30 minutes. Rubbing the eyes can cause an accidental scratching of the cornea.