[Multimodal evaluation of the ocular surface using a the new Lacrydiag device]

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Dry eye disease significantly impacts patient quality of life.
• Fluorescein tear break-up time (FBUT) is a common clinical sign.
• Non-invasive tear break-up time (NIBUT) using Placido disc analysis is a newer proposed method.

Purpose of the Study:

• To evaluate the automated NIBUT analysis using Lacrydiag.
• To compare NIBUT measurements with traditional dry eye diagnostic criteria.

Main Methods:

• Retrospective study of dry eye patients (Oxford score >1, OSDI score >22).
• Measurements included slit lamp examination, fluorescein BUT, Oxford score, Arita MGD score, Lacrydiag NIBUT, tear lake height, OSDI, and Schirmer's testing.
• Statistical analysis included Pearson's and Bland-Altman tests for correlation and concordance.

Main Results:

• NIBUT and FBUT were significantly correlated (R=0.139, P=0.042) and showed concordance (r=0.55, P=0.001).
• Mean NIBUT was 2.7 seconds longer than FBUT (P=0.001).
• NIBUT correlated with Oxford score (R=0.156, P=0.031) but not with Schirmer, OSDI, tear lake height, or Arita MGD scores.

Conclusions:

• Automated NIBUT offers a reproducible, fluorescein-independent alternative for tear film stability measurement.
• NIBUT's precise role in the diagnostic toolkit needs further definition due to weak correlations with other markers and significant difference from FBUT.
• Dry eye diagnosis should remain based on combined analysis of signs and symptoms.