From the Guidelines
The patch test for true tears, also known as the Schirmer test, uses small strips of filter paper to measure tear production, with the main material being standardized filter paper strips, typically 5mm wide and 35mm long, and the famous object present on the test being the millimeter markings on the filter paper strips. The Schirmer test is performed by placing a narrow filter-paper strip in the inferior cul-de-sac, usually the temporal one third of the lid, and aqueous tear production is measured by the length in millimeters that the strip wets during the test period, generally 5 minutes 1.
Key Points
- The test can be performed with or without topical anesthesia, depending on whether basal or reflex tear secretion is being evaluated 1.
- A Schirmer I (without topical anesthesia) of less than 5.5 mm of wetting after 5 minutes is diagnostic of aqueous tear deficiency 1.
- Measurements of less than 3 mm after 5 minutes, with anesthetic, are highly diagnostic of aqueous tear deficient dry eye 1.
- The normal value for adequate tear production is wetting of at least 15mm of the strip in 5 minutes, with values below 10mm indicating aqueous tear deficiency 1.
Diagnosis and Classification
The Schirmer test is important for diagnosing dry eye syndrome and other tear film abnormalities, and can be used to classify the subtype of dry eye disease (DED), including evaporative dry eye (EDE), aqueous deficiency dry eye, or a mixed-type dry eye 1.
- A positive MGD examination may be used to confirm the diagnosis of evaporative excess-type DED 1.
- An abnormal Schirmer’s test without anesthesia should be used to confirm aqueous deficiency-type DED 1.
- A positive MGD and an abnormal Schirmer’s test indicate mixed-type DED 1.
From the Research
Materials Used in the Schirmer Test
- Filter paper strips (usually 5 mm wide and 35 mm long) [ 2 ]
- Anaesthetic eye drops (optional)
- A ruler or caliper to measure the length of the wetted strip
Famous Objects Present on the Schirmer Test
- None specifically mentioned in the provided studies, but the test is often used in conjunction with other diagnostic tools such as:
- Ocular Surface Disease Index (OSDI) questionnaire [ 3, 4,5 ]
- Tear film break-up time (TBUT) test [ 4, 5 ]
- Fluorescein stain 5
- Meibomian gland (MG) secretion grading 5
Procedure and Interpretation
- The Schirmer test is performed by placing a filter paper strip in the corner of the eye, usually between the eyelid and the eye [ 2 ]
- The length of the wetted strip is measured after a specified time (usually 5 minutes) [ 2 ]
- A shorter length of wetting may indicate decreased tear production, which can be a sign of dry eye disease [ 2, 3,4,5 ]