Schirmer Tear Test
- A Schirmer tear test is a procedure that allows your veterinarian to determine if your pet is producing enough tears to keep the eyes healthy.
- Schirmer tear testing is used to diagnose a condition called keratoconjunctivitis sicca, more commonly known as dry eye.
What Is a Schirmer Tear Test?
Tears are produced by the eyes to reduce irritation, supply oxygen, and help keep the surface of the eyes moist. When tear production is inadequate, the eyes become painful, red, and irritated. This condition is commonly called dry eye, but the medical term is keratoconjunctivitis sicca (KCS).
A Schirmer tear test (STT) is used to determine if the eyes are producing adequate amounts of tears; therefore, it is the preferred test for diagnosing KCS.
How Is a Schirmer Tear Test Performed?
Performing an STT involves placing the tip of a small, thin strip of special filter paper inside the lower eyelid. The filter paper is specially formulated to absorb tears. The veterinarian places the tip of the filter paper inside the eyelid, closes the eye, and holds the paper there for exactly 60 seconds. The test strip has a printed ruler on one side, with a scale divided into millimeters. By comparing the amount of tears absorbed to a standard value, the veterinarian can tell if tear production is adequate.
Benefits of Schirmer Tear Testing
Chronically low tear production can cause persistent eye irritation, inflammation, and pain. Damage to the cornea (the thin, transparent covering of cells on the front of the eye) puts the patient at risk for further complications, including bacterial infections, corneal ulceration, and even loss of vision. Early diagnosis and prompt treatment of KCS is important for preventing eye irritation and further damage.
KCS can affect one or both eyes. If the condition is diagnosed before permanent damage is done, many animals respond well to medical treatment.