A tear meniscus height below what measurement is considered abnormal for aqueous deficient dry eye?

• A. < 0.3 mm
• B. < 0.2 mm
• C. < 0.1 mm
• D. < 0.4 mm

Answer: (B)

Tear meniscus height is a quick measure of how much tear fluid sits at the lower lid margin, reflecting tear volume on the ocular surface. In aqueous-deficient dry eye, tear production is reduced, so the tear meniscus becomes thinner. A height below 0.2 mm is considered abnormal because it indicates a significantly reduced tear reservoir, which aligns with decreased lacrimal output. Normal TMH is typically around 0.2–0.3 mm or greater, so crossing below 0.2 mm flags aqueous deficiency. Remember that this measurement can vary with blinking and technique, so it’s most informative when used alongside other tests like Schirmer, tear breakup time, and osmolarity.