. Author manuscript; available in PMC: 2018 Feb 14.

Published in final edited form as: Rheum Dis Clin North Am. 2016 Aug;42(3):531–551. doi: 10.1016/j.rdc.2016.03.010

Table 1.

Evaluation of dry eye

Observation or Test	What is Examined	Tools	Sign of Dry Eye
1. Direct Observation	Tear function, tear stability and ocular surface	Corneal light reflex biomicroscope (additional instruments are available in the research setting)	Tear film instability Ocular surface irregularity
1. Direct Observation	Meibomian gland disease	Biomicroscope	Presence of foamy debris

2. Osmolarity	Tear composition: levels of inflammatory mediators in tear film and conjunctiva	Osmometer (mostly limited to research settings but units are increasingly available for clinical practice)	Elevated osmolarity of the tear film

3. Fluorescein Tear Break-Up Time	Tear film stability	Fluorescein dye Slit-lamp	Rapid tear film breakup (<10 s)

4. Corneal Staining	Ocular surface evaluation	Fluorescein Rose bengal or lissamine green dye	Staining observed of mucus strands, filaments, and unprotected areas of the epithelium Staining patterns can designate severity of dry eye

5. Schirmer 1 Test or Phenol Red Thread Test	Tear secretion rate	Schirmer tear test strip Small thread impregnated with phenol red dye A fluorophotometer is more sensitive than either of these but is usually not available in the clinical setting	Schirmer 1: <5–7 mm of wetting after 5 min Phenol red thread test: <10 mm of wetting after 15 s