Variable

Group 1 (n = 28)

Group 2 (n = 23)

Group 3 (n = 19)

Group 4 (n = 30)

P value

Mean TBUT ± SD (sec)

14.8 ± 1.8

14.2 ± 2.1

13.6 ± 1.5

12.8 ± 1.2

<0.001

Mean Schirmer-1 measurement ± SD (mm in 5 min)

23.11 ± 6.2

21.6 ± 5

21.6 ± 3.8

18.8 ± 3.7

0.01

Mean OSDI score ± SD

11.8 ± 14.2

16.1 ± 15.6

19.6 ± 14.9

22.5 ± 14.7

< 0.001