Table 1.
Tear breakup time and Oxford Schema in relation to risk factors
| Variable | Tear breakup time <10 s | Tear breakup time >10 s | P value | Oxford Schema 0 | Oxford Schema 1 | P value |
|---|---|---|---|---|---|---|
| 1st year of residency | 33 (79 %) | 9 (21 %) | 0.008 | 28 (67 %) | 14 (33 %) | 0.06 |
| 2nd year of residency | 34 (63 %) | 20 (37 %) | 0.88 | 45 (83 %) | 9 (17 %) | 0.54 |
| 3rd year of residency | 32 (47 %) | 36 (53 %) | 0.14 | 58 (85 %) | 10 (15 %) | 0.29 |
| 4th year of residency | 23 (68 %) | 11 (32 %) | 0.23 | 22 (65 %) | 12 (35 %) | <0.001 |
| 5th year of residency | 7 (32 %) | 15 (68 %) | 0.02 | 19 (86 %) | 3 (14 %) | 0.33 |
| 6th year of residency | 10 (56 %) | 8 (44 %) | 0.91 | 16 (89 %) | 2 (11 %) | 0.27 |
| 7th year of residency | 1 (12 %) | 7 (88 %) | 0.01 | 8 (100 %) | 0 (0 %) | 0.16 |
| Chronic eye disease | 43 (58 %) | 31 (42 %) | 0.80 | 62 (84 %) | 12 (16 %) | 0.29 |
| Contact lenses | 13 (81 %) | 3 (19 %) | 0.04 | 9 (56 %) | 7 (44 %) | 0.02 |
| Refractive surgery | 19 (68 %) | 9 (32 %) | 0.21 | 24 (86 %) | 4 (14 %) | 0.39 |
| Allergies | 41 (66 %) | 21 (34 %) | 0.09 | 52 (84 %) | 10 (16 %) | 0.34 |
| Smoking | 21 (50 %) | 21 (50 %) | 0.32 | 32 (76 %) | 10 (24 %) | 0.53 |
| Hormonal contraceptives | 9 (56 %) | 7 (44 %) | 0.10 | 14 (87 %) | 2 (13 %) | 0.51 |
| Makeup use | 41 (71 %) | 17 (29 %) | 0.66 | 51 (88 %) | 7 (12 %) | 0.04 |
| Makeup use, 0–12 h | 23 (68 %) | 11 (32 %) | 0.54 | 34 (100 %) | 0 (0 %) | 0.001 |
| Makeup use, 12–24 h | 18 (75 %) | 6 (25 %) | 0.54 | 17 (71 %) | 7 (29 %) | 0.001 |
| Microscope use | 73 (68 %) | 35 (32 %) | 0.10 | 84 (78 %) | 24 (22 %) | 0.003 |