Tear Film Tests

Tear film testing encompasses a group of diagnostic tests that evaluate different aspects of your tear film—the thin layer of moisture that coats and protects the surface of your eye. Since the tear film has multiple components and functions, no single test captures the full picture. A comprehensive tear film assessment helps diagnose the type and severity of dry eye disease.

Why Tear Film Testing Is Done

• Diagnose dry eye syndrome
• Determine the type of dry eye (aqueous-deficient, evaporative, or mixed)
• Assess disease severity
• Guide treatment selection
• Monitor treatment response
• Evaluate before contact lens fitting or eye surgery

Overview of Tear Film Tests

Tear Quantity Tests

Schirmer Test

• Measures tear production using a paper strip
• Low values indicate aqueous deficiency
• Simple and widely available

Tear Stability Tests

Tear Break-Up Time (TBUT)

• Measures how quickly tears break apart on the eye surface
• Short TBUT indicates unstable tear film
• Key test for evaporative dry eye and MGD

Tear Composition Tests

Tear Osmolarity

• Measures tear concentration (saltiness)
• Elevated osmolarity indicates dry eye
• Considered a core diagnostic marker

MMP-9 Testing

• Detects inflammatory markers in tears
• Positive result indicates inflammatory dry eye
• Guides anti-inflammatory treatment

Structural Assessment

Meibography

• Images the meibomian (oil) glands in the eyelids
• Shows gland loss, shortening, or blockage
• Essential for evaluating MGD

Symptom Assessment

OSDI Questionnaire

• 12-question validated symptom survey
• Measures symptom severity and daily impact

DEQ-5 Questionnaire

• 5-question rapid screening tool
• Identifies patients likely to have dry eye

Putting It All Together

Comprehensive Dry Eye Workup

Test	What It Tells You
Schirmer	Are you making enough tears?
TBUT	Are your tears staying on the eye?
Osmolarity	Are your tears too concentrated?
MMP-9	Is there inflammation?
Meibography	Are the oil glands healthy?
OSDI/DEQ-5	How bad are the symptoms?

Common Patterns

Aqueous-Deficient Dry Eye:

• Low Schirmer test
• May have normal TBUT initially
• Often associated with autoimmune conditions

Evaporative Dry Eye (Most Common):

• Normal Schirmer test
• Short TBUT
• Meibomian gland changes on meibography
• Often related to blepharitis

Mixed Dry Eye:

• Abnormal in both quantity and stability
• May need combined treatment approach

Inflammatory Dry Eye:

• Positive MMP-9
• May have elevated osmolarity
• Benefits from anti-inflammatory medications

Frequently Asked Questions

Do I need all of these tests?

Not necessarily. Your doctor will select the most appropriate tests based on your symptoms and initial examination. Some patients need a comprehensive workup, while others may need only a few targeted tests.

How long does tear film testing take?

Individual tests take 1-10 minutes each. A complete dry eye evaluation, including multiple tests and examination, typically takes 30-60 minutes.

Will the tests hurt?

Most tear film tests cause minimal or no discomfort. The Schirmer test involves a paper strip in the eye, which can feel slightly unusual. Dye drops for TBUT may sting briefly. Overall, the tests are well tolerated.

How often should I have tear film testing?

Initially, a comprehensive evaluation establishes baseline measurements. Follow-up testing every few months helps monitor treatment response. Your doctor will recommend an appropriate schedule.

Can I wear contacts on the day of testing?

Your doctor may ask you to remove contacts before testing, as they can affect results. Follow your doctor's specific instructions about contact lens wear before your appointment.