Table 1 Descriptive characteristics of participants

Age (years old) (mean, s.d.)

30.75 (12.89)

Gender

9 Male (45 %)

Race

19 Chinese (95 %), 1 Indian (5%)

Symptomatic status for dry eye

13 (65 %)

Past ocular surgery

2 (10 %)

(1 bilateral LASIK, 1 bilateral strabismus surgery)

Current contact lens wear

2 (10 %)

Tear break-up time (s) (median, minimum, maximum)

3 (2, 7)

Tear break-up time <5 s

14 (70 %)

Presence of any corneal staining

8 (40 %)

Superior

0 (0 %)

Inferior

6 (30 %)

Nasal

1 (5 %)

Temporal

2 (10 %)

Central

3 (15 %)

Lipid layer thickness (nm) (mean, s.d.)

Investigator 1:

56 (17)

Investigator 2:

52 (13)

Combined:

54 (15)