Test	Abnormal Value	Significance of Abnormal Test
Schirmer	<5 mm/5 minute in either eye	Inadequate tear production
Ocular surface staining	Score ≥4 (von Bijsterveld) [15] Score ≥3 (SICCA) [17]	Damage to the ocular surface
Tear break up time	<10 seconds	Poor tear film stability, as seen in meibomian gland dysfunction
Tear osmolarity	≥308 mOsm/L in either eye	Excessive tear evaporation, lacrimal gland disease, or ocular surface inflammation

Abbreviation: SICCA, Sjögren's International Collaborative Clinical Alliance.