Doctors use the Schirmer's test to work out if a person's eyes make enough tears to keep the eyes moist. If the eyes don't produce enough moisture, a doctor may choose to treat the patient for dry eye.
This article will look at exactly what the test entails and when people can expect it to be used. Alternative options to the Schirmer's test will also be examined.
What is the Schirmer's test?
A Schirmer's test determines whether a person's eye produces enough tears to keep their eye moist and healthy. To conduct a Schirmer's test, a doctor places a piece of filter paper inside the lower eyelid of both eyes and the person closes their eyes.
After 5 minutes, the doctor removes the filter paper. The doctor then assesses how far the tears have travelled on the paper.
In general, the smaller the amount of moisture on the paper, the fewer tears that person has produced. The test is mainly performed on people experiencing symptoms of dry eye.
The test is noninvasive and has been used for around 100 years. Despite its long history of use, newer tests are being developed to catch additional cases of dry eye that the Schirmer's test cannot detect.
Why is the test used?
The Schirmer's test confirms and determines the severity of dry eye. Symptoms of dry eye include the following:
- excessive dryness in the eye
- persistent watering or tearing of the eye
- pain in the eye area
- feeling of something being in the eye
- chronic eye irritation
- sensitivity to light
The Schirmer's test may also be used to help diagnose Sjögren's syndrome. This is an autoimmune disorder that causes decreased function in the eye and salivary glands, resulting in dry eyes and mouth.
In these cases, the Schirmer's test is often used in conjunction with other tests to determine if Sjögren's is present.
Who should have a Schirmer's test?
Anyone who suspects that they suffer from dry eye should see an eye doctor promptly. Additionally, anyone with any of the following symptoms should also consult an eye doctor:
- sensitivity to light
- a stinging, burning, or scratchy sensation in the eyes
- difficulty with driving at night
- stringy mucus in or around the eyes
- eye redness
- blurred vision or eye fatigue
- a sensation of having something in the eyes
- difficulty wearing contact lenses
- watery eyes
When any of these symptoms persist for longer than a week, a doctor may send the person to a specialist or do a Schirmer's test to determine whether dry eye is the cause of the symptoms.
What to expect
Preparation for the Schirmer's test is minimal and simple. A person about to undergo the test will need to remove their contact lenses or glasses. In the case of contacts, the person should bring their glasses to wear after the test.
The Schirmer's test lasts about 5 minutes. Before the test, a doctor may ask the person about their tolerance for having something touching their eye. If they express discomfort at the idea of having something touching the eye, the doctor may use numbing drops.
The doctor then places the strip of paper inside the lower eyelids and the individual will keep their eyes closed for 5 minutes. Most people consider the test to be mildly irritating or uncomfortable.
After the test, people should avoid rubbing their eyes for about 30 minutes. Additionally, they should not wear contact lenses for about 2 hours following the test. Besides these two considerations, there are no other short- or long-term side effects to the procedure.
What do the results mean?
The results are based on the amount of the tears produced as measured on the strip of paper.
A normal level of production is considered to be over 10 millimeters (mm) of tears on the paper. Anything under 10 mm is considered to be an abnormally low level of tear production. A measurement of less than 5 mm is considered severe dry eye.
These measurements are directly affected by the age of the person being tested, as older people produce fewer tears.
Depending on the result, a doctor may recommend various treatments. The most typical treatment for chronic dry eyes is prescription eye drops. If a person's eyes are not severely dry, a doctor may advise a patient to use over-the-counter drops.
In some cases, additional treatment may be required to help treat and manage dry eyes.
Possible risks and considerations
There are no known risks to the Schirmer's test since it is a very simple procedure. However, it should be noted that the Schirmer's test does not always effectively diagnose cases of dry eye.
As a result, scientists are working on developing additional tests to help identify those groups of people for whom the Schirmer's test is not effective.
Other tests are being used and developed to help test for dry eye.
One test measures an iron-binding molecule called lactoferrin. The amount of lactoferrin present may be linked to tear production. As a result, people with dry eyes may find this test quite helpful as it can lead to specific treatment options for them.
Another test looks at the content of tears produced. In this test, tears are examined to see how much of an enzyme called lysozyme is present. Elevated levels in the eyes may cause dry eye.
A third alternative test uses special fluorescein eye drops. In this test, a person is given eye drops that contain a dye. In cases where patients do not have enough tears, it will take much longer for the eye to fully flush the dye out.
People with dry eyes may use eye drops to relieve their symptoms. These are available for purchase online.