Schirmer Test (Tear Secretion Test)

Key points of this disease

• The Schirmer test is a tear secretion function test devised by Schirmer in 1903, with over 100 years of clinical experience.
• A 5 mm × 35 mm graduated filter paper strip is placed in the conjunctival sac at the lateral one-third of the lower eyelid, and the wetting length (mm) is measured after 5 minutes.
• Schirmer test I (without topical anesthesia) is the most standard; normal value is 10 mm or more, and 5 mm or less is considered abnormal.
• Schirmer test II (nasal stimulation test) is added when test I shows low values, providing evidence for diagnosing severe dry eye such as Sjögren’s syndrome and GVHD.
• In the 2016 revised dry eye diagnostic criteria, BUT (tear break-up time) became the primary criterion, and Schirmer test is positioned as a reference indicator.
• Although the reproducibility of measurement is poor, it is still widely used as a screening test because the procedure is simple.
• Caution is needed in patients with lacrimal duct obstruction, as tear secretion may appear falsely high (pseudo-elevation).

1. What is the Schirmer test (tear secretion test)?

The Schirmer test (Schirmer test) is a tear secretion function test devised by Schirmer in 1903. A 5 mm × 35 mm filter paper with 1 mm interval markings is placed on the lower eyelid, and the length (mm) of wetting of the filter paper after 5 minutes is measured to quantitatively evaluate tear secretion.

With a history of over 100 years and simple operation, it is widely used worldwide. Its main purpose is to assist in the diagnosis and severity assessment of dry eye (tear-deficient type), and it also plays an important role in the diagnosis of systemic diseases associated with lacrimal gland hypofunction (e.g., Sjögren’s syndrome, graft-versus-host disease [GVHD]).

Dry eye is a frequently encountered condition in daily practice, with an estimated prevalence of 12.5% in men and 21.6% in women aged 40 years or older ¹⁾. The Schirmer test is standardly used for screening and objective evaluation of tear secretion.

Q Is the Schirmer test essential for diagnosing dry eye?

A

According to the 2016 revised diagnostic criteria for dry eye, diagnosis can be made based on “subjective symptoms + BUT ≤ 5 seconds,” and the Schirmer test is no longer mandatory. However, it remains important as a reference indicator when objective quantitative evaluation of tear secretion is needed or when differentiating severe dry eye such as Sjögren’s syndrome or GVHD.

2. Examination Technique and Procedure

Patient undergoing Schirmer test (filter paper placed on the lower eyelid of both eyes)

Sabage LE, et al. Conjunctival Swabs Reveal Higher Detection Rate Compared to Schirmer Strips for SARS-CoV-2 RNA Detection in Tears of Hospitalized COVID-19 Patients. J Clin Med. 2022;11(23):6929. Figure 1A. DOI: 10.3390/jcm11236929. PMCID: PMC9737489. License: CC BY 4.0.

A patient undergoing the Schirmer test, with 5 mm wide filter paper (Schirmer strips) placed on the lower eyelids of both eyes. The filter paper is fixed to the conjunctival sac at the lateral one-third of the lower eyelid, hanging down while absorbing tears. This corresponds to the filter paper placement method and measurement procedure described in the section “Examination Technique and Procedure.”

Types of Schirmer Test

There are three types of Schirmer test, used according to the purpose.

Method I (Standard Method)

Anesthetic eye drops: Not used (includes reflex secretion)

Indications: The most standard method used for general dry eye screening

Measurement content: Basal secretion + conjunctival sac storage + reflex secretion

Method I Modified (Under Anesthesia)

Anesthetic eye drops: Used (0.4% oxybuprocaine hydrochloride ophthalmic solution)

Indication: To evaluate pure basal tear secretion excluding reflex secretion

Measurement: Basal secretion + conjunctival sac reservoir volume

Method II (Nasal Stimulation Test)

Anesthetic eye drops: Not used

Indication: Performed additionally only in cases with low values in Method I

Measurement: Evaluation of reflex secretion (confirms reflex pathway via nasal mucosal stimulation)

Procedure for Schirmer Test Method I

The standard procedure for Schirmer Test Method I is described below.

1. Patient preparation: Have the patient sit and look slightly upward from the front
2. Filter paper preparation: Fold a 5 mm × 35 mm graduated filter paper at the 0 mm mark to create a hook
3. Filter paper placement: Hook the filter paper into the conjunctival sac at the lateral one-third of the lower eyelid. Be careful not to touch the cornea.
4. Measurement: Wait for 5 minutes with the eyes open and blinking allowed freely
5. Recording: Read and record the length (mm) of wetting from the fold

Procedure for Schirmer Test Method II (Nasal Stimulation Test)

This test is performed additionally only in patients with low tear secretion on the Schirmer I test.

1. Place the filter paper in the same way as in the Schirmer I test.
2. Insert a thin baby cotton swab deeply into the nasal cavity along the nasal septum to stimulate the mucosa.
3. Measure the length of wetting after 5 minutes.

Mechanical stimulation of the nasal mucosa induces reflex tear secretion via the trigeminal nerve. This test checks whether this pathway is intact.

Q Is the test painful?

A

The Schirmer I test does not use topical anesthesia, so there is a sensation of irritation or foreign body when the filter paper contacts the conjunctival sac. There is no severe pain, but tear secretion may be stimulated. In the modified Schirmer I test, anesthesia is performed with 0.4% oxybuprocaine hydrochloride eye drops before the test, reducing the irritation.

3. Interpretation of Normal and Abnormal Values

Normal and Abnormal Values for Each Test Method

The evaluation criteria for each test method are shown below.

Test Type	Normal Value	Borderline	Abnormal Value
Schirmer I test (old diagnostic criteria)	10 mm or more	5 to 10 mm	5 mm or less
Schirmer test I (current criteria)	10 mm or more	—	5 mm or less (reference value)
Schirmer test II	10 mm or more	—	10 mm or less

In the old dry eye diagnostic criteria (2006), a Schirmer test I value of 5 mm or less was considered positive¹⁾. In the current criteria revised in 2016, BUT is the main criterion, and a Schirmer test I value of 5 mm or less is treated as a reference value¹⁾.

Breakdown of tear secretion measured by each test method

Understanding the differences in what each test measures helps in accurately interpreting the test results.

Test type	Basal secretion volume	Conjunctival sac storage volume	Reflex secretion volume
Schirmer test I	○	○	○ (includes)
Schirmer test I modified	○	○	✕ (excludes)
Schirmer test II	○	○	○ (additional evaluation of reflex secretion by nasal stimulation)

Changes in diagnostic criteria

In the diagnostic criteria for dry eye before 2006, the Schirmer test I value was used as one of the main criteria. However, because the sensitivity and specificity of the Schirmer test are not as high as those of BUT, and the reproducibility of measurement is poor, the 2016 revised diagnostic criteria changed BUT ≤5 seconds to the main criterion, and the Schirmer test was changed to an auxiliary reference value ¹⁾. Combining BUT and Schirmer values helps differentiate dry eye subtypes (aqueous-deficient type and evaporative type).

4. Clinical significance and indications

The Schirmer test is widely used in the following clinical situations.

Dry eye screening: The Schirmer I test quantitatively assesses decreased tear secretion. In particular, low values in the Schirmer I test suggest the possibility of aqueous tear-deficient dry eye.

Evaluation of Sjögren’s syndrome and GVHD: For cases with low values on the Schirmer I test, the Schirmer II test is added. If the Schirmer II test also shows abnormal values of 10 mm or less, it indicates impairment of the reflex secretory pathway of the lacrimal gland, providing evidence to suspect severe dry eye such as Sjögren’s syndrome or GVHD.

Objective evaluation of dry eye treatment efficacy: By comparing Schirmer values before and after treatment, changes in tear secretion can be assessed numerically. It is used to confirm the therapeutic effect of eye drops (e.g., cyclosporine ophthalmic solution, diquafosol sodium ophthalmic solution).

Preoperative evaluation for ophthalmic surgery: It is used as a preoperative screening for cataract surgery and refractive surgery (e.g., LASIK) to check for the presence of dry eye. It provides a basis for explaining to patients the risk of dry eye worsening after surgery.

Position in TFOS DEWS III: In the international dry eye workshop (TFOS DEWS III), the Schirmer test is positioned as a test alongside tear meniscus height measurement and OCT measurement for tear volume assessment ²⁾. Although OCT meniscus measurement is superior in terms of sensitivity and specificity, the Schirmer test remains useful due to its widespread availability and simplicity ²⁾.

Q What diseases are suspected when the Schirmer II test is abnormal?

A

When the Schirmer II test shows abnormal values of 10 mm or less, it indicates a significant decrease in reflex tear secretion. There is a high possibility of severe dry eye with marked impairment of lacrimal gland function, such as Sjögren’s syndrome (primary or secondary) or GVHD (graft-versus-host disease) after hematopoietic stem cell transplantation. In these diseases, tear secretion is severely reduced, which also affects treatment choices such as the frequency of eye drop use and punctal occlusion (punctal plugs).

5. Precautions and Limitations

Variability in Measurements

Points to note in interpreting measurement results

The Schirmer test has very poor reproducibility. Care should be taken not to make a diagnosis based solely on a single measurement; it is important to make a comprehensive judgment in combination with other findings such as symptoms, BUT, and tear meniscus height.

The main factors affecting measurement values are as follows:

• Misalignment of the test strip: If the filter paper strongly contacts the cornea or conjunctiva, reflex tear secretion is induced by stimulation, resulting in falsely high values.
• Blinking and eye movements: In the Schirmer I test, since the eyes are open and blinking is free, eye movements during the test affect the measurement values.
• Environmental factors: Room temperature, humidity, and lighting brightness affect tear evaporation and indirectly cause measurement variability.

Causes of false high and false negative values

False high (higher than actual value):

• If there is punctal occlusion, nasolacrimal duct obstruction, or nasolacrimal duct stenosis, tears accumulate in the conjunctival sac due to impaired drainage. The Schirmer I test includes basal secretion, conjunctival sac storage, and reflex secretion, so the accumulated tears are added, resulting in an apparently high value.

False negative (lower than actual value):

• The Schirmer II test uses a reflex pathway via stimulation of the nasal septum. In patients with a history of nasal diseases such as allergic rhinitis, deviated nasal septum, or chronic rhinitis, the stimulation response may be weakened, leading to false negative results.

Summary of advantages and limitations

Advantages:

• No special equipment is required, and it can be performed immediately in an outpatient setting.
• The procedure is simple and can be performed in almost all ophthalmology clinics.
• Tear secretion can be quantitatively evaluated in millimeters.

Limitations:

• Low reproducibility (reliability) of measurements.
• Sensitivity and specificity are inferior to BUT and OCT meniscus measurement.
• Stimulation from filter paper placement disrupts the natural tear secretion environment.

6. Measurement Principle and Relationship with Other Tear Tests

Physical Measurement Principle

The Schirmer test is a physical method that uses the capillary action of filter paper to absorb and quantify tears. When the graduated filter paper absorbs tears, the liquid advances linearly due to capillary force. The wetting length after 5 minutes serves as a surrogate indicator of tear secretion. This test is the simplest method for evaluating tear volume, requiring no biochemical or optical analysis.

Position in Tear Testing

There are several tests for tear evaluation, each assessing different aspects.

Evaluation of tear film stability (BUT test): The tear film breakup time is measured under fluorescein staining. It evaluates the “quality (stability)” of tears. It has been adopted as the primary criterion in the 2016 revised diagnostic criteria for dry eye ¹⁾.

Evaluation of tear volume (Schirmer test, OCT meniscus measurement): The Schirmer test assesses secretion volume, while OCT (optical coherence tomography) measurement of the lower tear meniscus height evaluates storage volume. OCT meniscus measurement is non-invasive, highly quantitative and reproducible, with a threshold of 0.2 mm or less indicating a decrease ²⁾.

Subtype classification of dry eye: In aqueous-deficient dry eye, the Schirmer test tends to show low values. In evaporative dry eye, BUT is shortened but Schirmer values are often within the normal range. Combining both tests enables differentiation of subtypes ¹⁾.

Tear osmolarity measurement: In recent years, tear osmolarity has gained attention as a biomarker for dry eye. Devices with a positive threshold of 316 mOsm/L or higher are commercially available, allowing complementary evaluation with Schirmer ²⁾.

7. Latest Research and Future Perspectives

Medical Disclaimer

The following content is currently under research or development and may differ from standard tests and treatments available in general hospitals. This is reference information for professionals regarding future medical developments.

Quantitative Measurement of Tear Meniscus by OCT

Measurement of tear meniscus height using anterior segment OCT is being studied as a non-invasive, quantitative, and highly reproducible method for tear volume assessment. It has been shown to have superior sensitivity and specificity compared to the Schirmer test, and may potentially replace Schirmer as a standard test in the future ²⁾. Currently, complementary use of both tests is recommended.

Improvements to the Schirmer Test

Research has been reported on an improved Schirmer test using a new filter paper material with optimized fiber uniformity and water absorption rate, replacing conventional paper filter paper. The aim is to reduce the coefficient of variation of measurements and improve reproducibility. International efforts toward standardization are ongoing.

8. References

1. 島﨑潤, 横井則彦, 渡辺仁, 他; ドライアイ研究会. ドライアイ診療ガイドライン. 日眼会誌. 2019;123(5):489-592.
2. Jones L, Downie LE, Korb D, et al. TFOS DEWS III Management and Therapy of Dry Eye Disease. Ocul Surf. 2025.