Can the Schirmer test be positive in one eye and negative in the other in Sjögren's syndrome?

Yes, Schirmer Test Asymmetry is Common in Sjögren's Syndrome

Yes, the Schirmer test can absolutely be positive in one eye and negative in the other in Sjögren's syndrome—this asymmetry is well-recognized and does not exclude the diagnosis. In fact, the diagnostic criteria for Sjögren's syndrome only require an abnormal Schirmer test result (≤5 mm/5 minutes without anesthesia) in at least one eye, not both eyes 1, 2, 1.

Why Asymmetry Occurs

The Schirmer test is known for its variable and inconsistent results, even in the same patient 1. This variability stems from:

• Test-to-test variability: The Schirmer test has inherently poor reproducibility, with studies showing that even when positive in one eye, it may only remain positive in that same eye 77.4% of the time when repeated 3
• Bilateral disease with asymmetric severity: Sjögren's syndrome causes lymphocytic infiltration of lacrimal glands, but this infiltration doesn't necessarily affect both glands equally or simultaneously
• Poor specificity: The Schirmer test has only 51% specificity for dry eye diagnosis, meaning it produces inconsistent results even in disease states 1

Diagnostic Implications

For Sjögren's Syndrome Diagnosis

The 2012 American College of Rheumatology/European League Against Rheumatism classification criteria specifically state that a Schirmer test result of ≤5 mm/5 minutes in at least one eye (without anesthesia) scores 1 point toward the diagnosis 1. You need a total score of ≥4 points from the weighted criteria to meet diagnostic criteria for primary Sjögren's syndrome.

Clinical Approach

When evaluating for Sjögren's syndrome with asymmetric Schirmer results:

1. Accept the abnormal result: If one eye shows ≤5 mm/5 minutes, this meets the ocular criterion regardless of the other eye's result
2. Don't rely on Schirmer alone: The guidelines explicitly warn that Schirmer test "should not be used as the sole criterion for diagnosing dry eye" 1
3. Add confirmatory tests: Combine with:
   • Ocular staining score (≥5) or van Bijsterveld score (≥4) using lissamine green or rose bengal—this has better diagnostic performance with 89% specificity 4
   • Serologic testing for anti-SSA/Ro antibodies (most specific at 100%) 4, 5
   • Labial salivary gland biopsy (gold standard with 100% sensitivity and specificity) 5

Important Caveats

• Serially consistent results matter more: While a single abnormal Schirmer test in one eye can be nonspecific, "serially consistent low results are strongly suggestive of aqueous tear deficiency" 1
• Consider repeating the test: If clinical suspicion is high but results are borderline, repeat testing may increase diagnostic yield, though the gain is limited 3
• Beware of age effects: Schirmer test results can be influenced by age in elderly patients, though this is less problematic than with other tear tests 6

Bottom line: Unilateral positive Schirmer test results are diagnostically valid for Sjögren's syndrome and should prompt completion of the full diagnostic workup rather than dismissal of the diagnosis.