The Application of Strip Meniscometry to the Evaluation of Tear Volume in Mice

Purpose: Strip meniscometry quantitatively measures the volume of tears in the tear meniscus and has been reported to diagnose dry eyes in clinical settings conveniently, easily, and rapidly. In this study, we used a modified strip meniscometry to assess the applicability of measuring the tear volume in mice in experimental settings. Methods: Dry eye was induced in 11 9-week-old C57BL/6J wild-type male mice (11 right eyes) by exposing them to an air fan inside a small compartment for 5 hours for 2 consecutive days. Tear function tests, including the SMTube for mice (SMTM) for tear volume evaluation, break-up time, fluorescein staining score, and lissamine green staining score, were performed. The correlation between SMTM and other tear function parameters was assessed. Results: The mean SMTM value was 3.89 ± 0.603 mm before and 3.09 ± 0.625 mm after dry environment exposure (P = 0.0078*). The Spearman's correlation by rank test showed a strong positive correlation between SMTM and tear film break-up time and a strong linear negative correlation with fluorescein and lissamine green values. Conclusions: The SMTM was capable of rapidly measuring the minimum tear volume in mice and correlated well with tear function parameters and appears to be a promising new modality in the evaluation of dry eyes in mice.