Seasonality of Tear Meniscus Volume and Dry Eye-Related Symptoms - A Cross-Sectional Retrospective Cohort Study.

Purpose: We aimed to determine the seasonal variation in the tear meniscus level on strip meniscometry and its association with ocular parameters and symptoms. In Japan, there are four distinct seasons characterized by marked differences in temperature and humidity, which may contribute to an observed seasonality of ocular surface symptoms.

Methods: We conducted a cross-sectional study in two Japanese clinics and recruited first-visit patients for 3 years. Tear strip meniscometry, tear break-up time (BUT), Schirmer test, and corneal staining were examined, and major ocular symptoms (dryness, irritation, pain, fatigue, blurred vision, and photophobia) were determined through interviews.

Results: The 1196 participants had a mean age of 58.9±15.2 years; 37.1% were of male sex. Strip meniscometry values and BUT revealed significant seasonality with one-way analysis of variance. The mean strip meniscometry value (mm) was 2.15±2.59 in spring (=0.025 vs winter), 2.37±2.79 in summer (<0.001), 2.38±2.80 in fall (<0.001), and 1.64±2.29 in winter. Regression analysis indicated that strip meniscometry levels were correlated with BUT (<0.001), Schirmer test values (<0.001), corneal staining scores (=0.022), and presence of dryness (<0.001).

Conclusion: Strip meniscometry values exhibited distinct seasonality, being lowest in winter when the ambient condition is dry and cool, and were correlated with BUT, Schirmer test values, corneal staining scores, and the presence of subjective dryness.