Table 1: Diagnostic tests and normal values.

TestNormal values

Tear film breakup time (TBUT)>10 sec
Noninvasive breakup time (NIBUT)40 sec–60 sec
Epithelial stainingNo visible staining
Schirmer test (basic)>5 mm after 5 minutes
Schirmer I test (without topical anesthesia)>10 mm after 5 minutes
Schirmer II test/Jones test (with anesthesia)>15 mm after 5 minutes
Tear function index>96
Tear osmolarity<312–318 mOsm/L
Impression cytologyNormal appearance of cells
Tear fluid protein immunoassayTotal lysozyme reactivity TLR <1.0
Lactoferrin 1.42 mg/mL (abnormal value <1)