Table 2. Demographic finding between short break up time.
| Variables | TBUT<blinking interval Unstable tear group | TBUT>blinking interval Stable tear group | Total | P |
| Number | 680 (79.2) | 178 (20.7) | 858 | |
| Age (y) | ||||
| 20-29 | 38 (5.6) | 20 (11.2) | 58 (6.8) | <0.001a |
| 30-39 | 140 (20.6) | 56 (31.5) | 196 (22.8) | |
| 40-49 | 292 (42.9) | 73 (41.0) | 365 (42.5) | |
| 50-59 | 193 (28.4) | 28 (15.7) | 221 (25.8) | |
| 60-69 | 17 (2.5) | 1 (0.6) | 18 (2.1) | |
| Sex | ||||
| M | 537 (79.0) | 118 (66.3) | 655 (76.3) | 0.001b |
| F | 143 (21.0) | 60 (33.7) | 203 (23.7) | |
| VDT use (h) | ||||
| 0-4 | 19 (2.8) | 0 (0) | 19 (2.2) | 0.009a |
| 4-8 | 294 (43.2) | 64 (36.0) | 358 (41.7) | |
| ≥8 | 367 (54.0) | 114 (64.0) | 481 (56.1) | |
| Current history of certain common systemic diseases | ||||
| Hypertension | 55 (8.1) | 9 (5.1) | 64 (7.5) | 0.201b |
| Diabetes mellitus | 12 (1.8) | 2 (1.1) | 14 (1.6) | 0.746b |
| Stress | ||||
| No | 263 (38.7) | 64 (36.0) | 327 (38.1) | 0.544b |
| Yes | 417 (61.3) | 114 (64.0) | 531 (61.9) | |
| Dry eye symptom | ||||
| Frequency | 2.6±2.6 | 2.9±2.8 | 2.6±2.6 | 0.184c |
| Intensity | 0.9±1.8 | 1.1±2.2 | 0.9±1.9 | 0.130c |
| Schirmer value (mm) | 17.5±11.6 | 21.1±11.5 | 18.3±11.7 | <0.001c |
| TBUT (s) | 3.7±2.6 | 5.7±2.7 | 4.1±2.8 | <0.001c |
| Blinking count | 7.6±7.0 | 22.7±9.8 | 10.7±9.8 | <0.001c |
| Eye opening time (s) | 21.9±21.9 | 3.35±1.95 | 18.0±20.9 | <0.001c |
| Epithelial staining (points) | ||||
| 0-2 | 612 (90.0) | 151 (84.8) | 763 (88.9) | 0.081c |
| 3-6 | 68 (10.0) | 26 (14.6) | 94 (11.0) | |
| 7-9 | 0 (0) | 1 (0.6) | 1 (0.1) | |
| Mean±SD | 0.8±1.2 | 1.0±1.5 | 0.9±1.3 | |
TBUT: Tear film break up time; VDT: Visual display terminal. aU-test, bFishers exact test, ct-test.
mean±SD, n (%)