Dry eye symptoms fluctuate throughout the day despite stable clinical measures

A study found a persistent mismatch between patient-reported symptoms and objective signs of dry eye disease (DED), with patients reporting symptom fluctuations throughout the day despite a lack of clinically meaningful diurnal changes in tear film parameters. The findings suggest that time of day may have limited importance for objective dry eye assessment, while symptom variability may be driven by factors not captured by standard clinical testing.

The study, which included 1,044 dry eye clinic patients, assessed associations between time of day and both subjective symptom scores and objective clinical measures. Diurnal rhythmicity was examined with single-component cosinor analysis based on a 24-hour cycle.

Although statistically significant associations were identified between time of day and objective tear film parameters, the correlations were clinically negligible. No meaningful diurnal variation was detected in quantitative clinical measures.

Reference

Bair JA, Khan AZ, Yazdani M, et al. Impact of Time of Day on Dry Eye Disease: Findings from a Large Dry Eye Clinic Cohort. Clin Ophthalmol. 2026;20:593926. doi: 10.2147/OPTH.S593926. PMID: 42261474; PMCID: PMC13242849.