Tear-fluid biopsy

Tear-fluid biopsy tests a microliter-scale tear sample at the point of care for dry eye disease, ocular allergy and inflammatory biomarkers, offering a diagnostic window that avoids blood draw or invasive tissue sampling entirely. Trukera Medical’s tear osmolarity system (built on the TearLab platform lineage) measures tear-film osmolarity as the reference biomarker for dry eye disease severity, with its dynamic temperature-compensation technology documented in a dedicated patent filing and distributed in some markets through a Topcon Healthcare partnership. Lacrisciences’ LacryDx test (developed by Advanced Tear Diagnostics) measures tear IgE to diagnose allergic conjunctivitis at the point of care. QuidelOrtho’s InflammaDry test detects elevated MMP-9, an inflammatory marker associated with dry eye disease, though a 2026 industry report flagged a supply disruption affecting at least one distribution channel for the product. In France, DiagnosTear’s TearX platform recently reported interim clinical study results showing excellent correlation between its Red Eye test and quantitative ELISA testing, alongside French regulatory approval and a new clinical study initiated with Alyatec.

The key directions of tear-fluid biopsy are:

1. Tear osmolarity testing (Tear Osmolarity Testing): measuring the salt concentration of tear film as the reference biomarker for dry eye disease severity and treatment monitoring — Trukera Medical.
2. Tear IgE allergy testing (Tear IgE Allergy Testing): point-of-care immunoglobulin E measurement in tears to diagnose allergic conjunctivitis without a blood draw — Lacrisciences’ LacryDx.
3. Tear inflammatory biomarker testing (Tear Inflammatory Biomarker Testing): lateral-flow detection of inflammatory markers such as MMP-9 associated with dry eye disease — QuidelOrtho’s InflammaDry.
4. Point-of-care tear ELISA-correlated testing (Point-of-Care Tear ELISA Testing): rapid tear tests validated against quantitative laboratory ELISA reference methods — DiagnosTear’s TearX.

Sectoral value chain#

[tear sample collection] ──> [point-of-care analyzer reading] ──> [biomarker quantification]
                                                    │
                                       (clinical report / diagnosis)
                                                    │
                                                    ▼
[treatment decision (dry eye/allergy/inflammation)] <─── [regulatory clearance] <─────┘

Value chain levels#

Cross-cutting technologies of the sector:

• Osmolarity measurement (Tear Osmolarity Testing): electrical impedance or freezing-point-depression methods quantify tear-film salt concentration, the established reference biomarker for dry eye severity.
• Point-of-care immunoassay (Tear IgE Allergy Testing / Tear Inflammatory Biomarker Testing): lateral-flow or microfluidic immunoassay chemistry detects specific proteins (IgE, MMP-9) in a microliter tear sample without a central laboratory.
• ELISA-correlated rapid testing (Point-of-Care Tear ELISA Testing): point-of-care tear tests validated directly against quantitative ELISA reference methods, as DiagnosTear’s interim clinical data demonstrates for its Red Eye test.

The stack applies distinct point-of-care chemistries — osmolarity measurement, lateral-flow immunoassay, and ELISA-correlated rapid testing — to the same microliter tear sample to reach different diagnostic endpoints.

1. Tear osmolarity measurement (Tear Osmolarity Testing):
   • Trukera Medical’s system quantifies tear-film salt concentration with dynamic temperature compensation, the established quantitative reference for dry eye disease severity and treatment monitoring.
2. Point-of-care IgE and inflammatory-marker immunoassay (Tear IgE Allergy Testing / Tear Inflammatory Biomarker Testing):
   • Lacrisciences’ LacryDx detects tear IgE for allergic conjunctivitis, and QuidelOrtho’s InflammaDry detects elevated MMP-9 for dry eye inflammation, both using lateral-flow or microfluidic immunoassay chemistry that returns a result at the point of care.
3. ELISA-correlated rapid diagnostics (Point-of-Care Tear ELISA Testing):
   • DiagnosTear’s TearX Red Eye test is validated directly against quantitative ELISA reference methods, with interim 2026 clinical data reporting excellent correlation between the rapid test and the laboratory gold standard.
4. Regulatory-cleared point-of-care ophthalmic diagnostics:
   • Each platform’s biomarker claim clears its own regulatory review (FDA 510(k) or EU IVDR), reflecting the category’s maturity as an established, cleared point-of-care diagnostic tier rather than a research-stage technology.