What is the current dilemma with Interferometry?

• A. In dogs the lower scores correlate with more severe disease and gray finding; in humans higher scores mean more severe disease and gray is considered normal; this requires more consistent grading
• B. Interferometry is unreliable and unusable
• C. It can only measure lipid layer thickness
• D. It is invasive

Answer: (A)

Interferometry provides a map of tear film lipid layer thickness that clinicians interpret with a scoring system. The current dilemma is the lack of consistent grading across species. In humans, higher scores correlate with more severe disease and gray is considered normal, whereas in dogs lower scores correlate with more severe disease and the gray patterns can be interpreted differently. This mismatch makes cross-species and cross-study comparisons unreliable and hampers standard clinical decision-making. The instrument itself is noninvasive and can offer more than just lipid thickness, but without species-specific, standardized scoring data, interpretation remains inconsistent. Addressing this requires validated scoring schemes and normative data for each species to ensure results are comparable and meaningful.