Objective:

To quantify the association between glycemia (blood sugar levels) and tear-film homeostasis across the non-diabetes to diabetes continuum.

Key Findings:

• Mean NIBUT was 11.8, 10.5, and 9.2 seconds across non-diabetes, prediabetes, and diabetes, respectively (p-trend < 0.001).
• Mean Schirmer I scores were 13.8, 12.1, and 10.4 mm across the same strata (p-trend < 0.001).
• For every 1% increase in HbA1c, NIBUT decreased by 0.72 seconds and Schirmer by 1.15 mm (both p < 0.001).
• The odds of dry eye disease (DED) increased with higher HbA1c (aOR 1.31; p < 0.001).
• DED prevalence was 24.0%, 34.0%, and 51.0% in non-diabetes, prediabetes, and diabetes, respectively.

Interpretation:

Higher glycemic status correlates with shorter tear film stability and lower tear secretion, indicating a potential link between glycemia and dry eye disease, which may impact clinical management.

Limitations:

• Cross-sectional design limits causal inference.
• Study conducted at a single center may affect generalizability and introduce biases.

Conclusion:

Higher glycemic status, including prediabetes, is associated with reduced tear film stability and increased dry eye disease risk, warranting further longitudinal studies to explore these associations, particularly in diverse populations.