Cox-regression models for the follow-up duration in 1633 patients who completed the follow-up
| Variable | Mean (SD) | Median (range) | p Value | HR (95% CI) | Total |
| Age group (years) | |||||
| <30 | 10.6 (3.9) | 10 (7–29) | <0.001 | 2.97 (2.53 to 3.50) | 420 |
| 30–60 | 11.6 (4.4) | 11 (7–42) | 1.77 (1.54 to 2.04) | 835 | |
| >60 | 12.6 (4.1) | 14 (7–35) | 1.00 | 378 | |
| Sex | |||||
| Male | 10.9 (4.4) | 10 (7–36) | <0.001 | 1.56 (1.41 to 1.72) | 744 |
| Female | 12.2 (4) | 12 (7–42) | 1.00 | 889 | |
| Predisposing factor | |||||
| Mixed factors | 14.2 (6.3) | 14 (7–42) | <0.001 | 0.29 (0.24 to 0.35) | 220 |
| Contact lens wearing | 12.5 (3.5) | 12 (7–32) | 0.42 (0.36 to 0.48) | 524 | |
| Corneal trauma | 12.5 (3.2) | 12 (7–23) | 0.41 (0.33 to 0.51) | 110 | |
| Ocular disease | 11 (3.9) | 10 (7–26) | 0.53 (0.46 to 0.62) | 396 | |
| Systemic illness | 10.4 (3.7) | 10 (7–22) | 0.60 (0.46 to 0.77) | 75 | |
| Undefined | 8.8 (2.4) | 7 (7–17) | 1.00 | 308 | |
| Presenting visual acuity | |||||
| ⩾6/6 | 10.2 (2.8) | 10 (7–21) | <0.001 | 4.02 (2.82 to 5.71) | 685 |
| 6/9 | 11.3 (3.6) | 10 (7–28) | 3.11 (2.18 to 4.44) | 359 | |
| 6/12 | 12.4 (4.8) | 12 (7–36) | 2.39 (1.67 to 3.42) | 303 | |
| 6/18 | 13.1 (5.2) | 12 (7–36) | 2.14 (1.47 to 3.11) | 140 | |
| 6/24 | 13.8 (4.7) | 14 (7–35) | 1.91 (1.26 to 2.89) | 67 | |
| 6/36 | 15.3 (5.7) | 16 (7–35) | 1.56 (1.00 to 2.45) | 44 | |
| ⩽6/60 | 19.1 (6.4) | 20 (10–42) | 1.00 | 35 | |
| Ulcer location | |||||
| Central | 14.4 (5.3) | 13 (7–42) | <0.001 | 0.49 (0.41 to 0.57) | 411 |
| Paracentral | 12.4 (4.1) | 12 (7–35) | 0.60 (0.50 to 0.71) | 252 | |
| Midperipheral | 10.2 (3.1) | 10 (7–24) | 0.88 (0.77 to 1.01) | 629 | |
| Marginal | 10.2 (2.8) | 10 (7–22) | 1.00 | 341 | |
| Ulcer size | |||||
| Large | 22.8 (6.5) | 20 (14–42) | <0.001 | 0.21 (0.14 to 0.30) | 38 |
| Medium | 17.9 (5.6) | 18 (10–35) | 0.33 (0.27 to 0.42) | 100 | |
| Small | 10.9 (3.2) | 10 (7–28) | 1.00 | 1495 | |
| Microbial infections | |||||
| Bacteria+acanthamoeba | 29.4 (5.9) | 29 (22–42) | <0.001 | 0.08 | 11 |
| Bacteria+fungus | 23 (3.4) | 24 (17–72) | 0.11 (0.05 to 0.27) | 8 | |
| Bacteria+virus | 12.8 (3.7) | 12 (7–27) | 0.32 (0.22 to 0.47) | 62 | |
| Bacteria+chlamydia | 12.5 (4.5) | 12 (7–20) | 0.62 (0.38 to 1.37) | 12 | |
| Viral | 12.1 (3.8) | 10 (7–24) | 0.44 (0.33 to 0.60) | 423 | |
| Pure bacterial | 11.6 (4.2) | 11 (7–35) | 0.67 (0.50 to 0.90) | 650 | |
| Negative cultures | 10.5 (2.9) | 10 (7–19) | 0.75 (0.55 to 1.01) | 415 | |
| Undefined | 8 (2) | 7 (7–14) | 1.00 | 52 |