Diagnostic Tests and Understanding Your Results
At a Glance
A single test cannot diagnose Dry Eye Syndrome. Doctors use a combination of a symptom questionnaire (OSDI) and clinical signs like tear break-up time (TBUT), tear osmolarity, and surface staining to accurately diagnose the disease and determine your specific subtype.
Understanding the results of a dry eye exam can feel like trying to solve a puzzle with missing pieces. Because Dry Eye Syndrome (DES) is a multifactorial disease, your doctor cannot rely on a single “gold standard” test. Instead, they look for a convergence of data points that reveal how and why your tear film has lost its balance (homeostasis) [1][2]. Return to Home
The Global Diagnostic Standard
The TFOS DEWS II report established a specific diagnostic algorithm to ensure accuracy. A diagnosis of dry eye is typically confirmed when a patient has significant symptoms plus at least one objective clinical sign [1].
1. The Symptom Score (OSDI)
The first step is a validated questionnaire, most commonly the Ocular Surface Disease Index (OSDI).
- What it measures: Your subjective level of discomfort and how dryness affects your daily life.
- The Threshold: A score of 13 or higher is considered positive for dry eye symptoms [1].
2. The Clinical Signs
If your symptom score is high, your doctor will look for at least one of the following “red flags” in your tear film [1]:
- Tear Break-Up Time (TBUT or NITBUT): This measures how many seconds your tear film remains stable on the eye before it “breaks” and exposes the surface. A result of less than 10 seconds is a primary sign of an unstable tear film [1][3].
- Tear Osmolarity: This measures the concentration of salts in your tears. When tears evaporate too quickly, they become “salty” (hyperosmolarity), which damages the eye’s surface [4]. A reading of 308 mOsm/L or higher in either eye (or a difference of more than 8 mOsm/L between the two eyes) is a key indicator of disease [1][5].
- Ocular Surface Staining: Your doctor uses special dyes (like fluorescein or lissamine green) to highlight damaged areas. Seeing more than 5 spots (lesions) on the cornea is a clinical sign of surface damage [1].
Common Diagnostic Tests Explained
In addition to the core criteria above, your doctor may use other tests to pinpoint your specific subtype:
| Test Name | What it Measures | Why it Matters |
|---|---|---|
| Schirmer Test | Tear Volume | Measures how many millimeters of tears you produce in 5 minutes. Lower numbers suggest Aqueous Deficient dry eye [6]. |
| Meibography | Gland Structure | A quick, painless imaging test that uses infrared light to take a “picture” of the meibomian glands in your eyelids to see if they are vanishing or blocked [1]. |
| MMP-9 Testing | Inflammation | A painless swab that checks for a specific inflammatory marker on the eye’s surface [7]. |
Why One Test is Never Enough
It is common for dry eye tests to be “discordant”—meaning you might “fail” the osmolarity test but “pass” the Schirmer test. Relying on just one result carries a high risk of misdiagnosis [8].
For example, a patient with Evaporative Dry Eye might produce plenty of tears (passing a Schirmer test) but have tears that are too salty (failing an osmolarity test) because those tears lack the protective oil layer needed to stop evaporation [1][4]. A comprehensive workup allows your doctor to see the full picture and tailor a treatment plan to your specific biological “leak” [8][9].
Common questions in this guide
What is an OSDI score for dry eye?
What does tear osmolarity measure?
What is a normal tear break-up time (TBUT)?
Why did I pass the Schirmer test but still have dry eye?
What does a meibography test show?
Questions to Ask Your Doctor
Curated prompts to bring to your next appointment.
- 1.What was my OSDI score, and how does it compare to the threshold for a dry eye diagnosis?
- 2.Can you explain what my tear osmolarity reading says about the 'saltiness' or health of my tear film?
- 3.During my exam, how many seconds did my tear film remain stable before breaking up (TBUT)?
- 4.Was there evidence of ocular surface staining, and did it involve the cornea, conjunctiva, or both?
- 5.How do my results for tear volume (Schirmer test) compare to my results for tear stability (TBUT)?
- 6.Based on all these tests, do I have a 'pure' subtype of dry eye, or is it a mixed case?
Questions For You
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References
References (9)
- 1
TFOS DEWS II Diagnostic Methodology report.
Wolffsohn JS, Arita R, Chalmers R, et al.
The ocular surface 2017; (15(3)):539-574 doi:10.1016/j.jtos.2017.05.001.
PMID: 28736342 - 2
Relative importance of tear homeostatic signs for the diagnosis of dry eye disease.
Wolffsohn JS, Travé-Huarte S, Stapleton F, et al.
The ocular surface 2025; (36()):151-155 doi:10.1016/j.jtos.2025.01.010.
PMID: 39848540 - 3
Intense pulsed light therapy: A promising complementary treatment for dry eye disease.
Mejía LF, Gil JC, Jaramillo M
Archivos de la Sociedad Espanola de Oftalmologia 2019; (94(7)):331-336 doi:10.1016/j.oftal.2019.03.009.
PMID: 31079987 - 4
Hyperosmolar Tears Induce Functional and Structural Alterations of Corneal Nerves: Electrophysiological and Anatomical Evidence Toward Neurotoxicity.
Hirata H, Mizerska K, Marfurt CF, Rosenblatt MI
Investigative ophthalmology & visual science 2015; (56(13)):8125-40 doi:10.1167/iovs.15-18383.
PMID: 26720465 - 5
Safety and efficacy of cyclosporine (0.05% versus 0.09%) in dry eye disease. Is it the strength of cyclosporin that really matters?
Rajpoot M, Singh D, Pandey K, Bhargava R
Nepalese journal of ophthalmology : a biannual peer-reviewed academic journal of the Nepal Ophthalmic Society : NEPJOPH 2022; (14(28)):64-77 doi:10.3126/nepjoph.v14i2.38928.
PMID: 37609968 - 6
Prevalence and characteristics of dry eye disease in Parkinson's disease: a systematic review and meta-analysis.
Nagino K, Sung J, Oyama G, et al.
Scientific reports 2022; (12(1)):18348 doi:10.1038/s41598-022-22037-y.
PMID: 36319814 - 7
Definition and Diagnostic Criteria of Dry Eye Disease: Historical Overview and Future Directions.
Shimazaki J
Investigative ophthalmology & visual science 2018; (59(14)):DES7-DES12 doi:10.1167/iovs.17-23475.
PMID: 30481800 - 8
Diagnosing dry-eye: Which tests are most accurate?
Papas EB
Contact lens & anterior eye : the journal of the British Contact Lens Association 2023; (46(5)):102048 doi:10.1016/j.clae.2023.102048.
PMID: 37544866 - 9
Variability of Tear Osmolarity Measurements With a Point-of-Care System in Healthy Subjects-Systematic Review.
Baenninger PB, Voegeli S, Bachmann LM, et al.
Cornea 2018; (37(7)):938-945 doi:10.1097/ICO.0000000000001562.
PMID: 29620566
This page explains Dry Eye Syndrome diagnostic testing for educational purposes. Your eye care provider is the best source for interpreting your specific exam results and developing a treatment plan.
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