Predisposing factors in 1786 patients with infectious keratitis
| Predisposing factor | n (%) | Total (%) | 95% CI |
| Contact lens wear | |||
| Soft | 534 (29.9) | 554 (31) | 29 to 33 |
| Rigid gas permeable | 13 (0.7) | ||
| Hard | 7 (0.4) | ||
| Ocular diseases | |||
| Previous keratitis | 173 (9.7) | 424 (23.7) | 22 to 26 |
| Blepharitis | 41 (2.3) | ||
| Dacryocystitis | 40 (2.3) | ||
| Dry eye | 27 (1.5) | ||
| Chronic conjunctivitis | 26 (1.5) | ||
| Chronic marginal keratitis | 25 (1.4) | ||
| Exposure keratitis | 15 (0.8) | ||
| Lid margin position disorders | 13 (0.7) | ||
| Recurrent erosion syndrome | 11 (0.6) | ||
| Allergic conjunctivitis | 11 (0.6) | ||
| Previous ocular surgery | 10 (0.6) | ||
| Glaucoma | 9 (0.5) | ||
| Orbital cellulitis | 6 (0.3) | ||
| Scleritis | 5 (0.3) | ||
| Endophthalmitis | 4 (0.2) | ||
| Lid cancer | 3 (0.2) | ||
| Ocular radiation | 3 (0.2) | ||
| Corneal melt | 2 (0.1) | ||
| Corneal trauma | |||
| Mechanical trauma | 69 (3.9) | 115 (6.4) | 5 to 8 |
| Corneal foreign body | 26 (1.5) | ||
| Chemical burn | 9 (0.5) | ||
| Thermal burns | 6 (0.3) | ||
| Phototoxicity (ultraviolet rays) | 5 (0.3) | ||
| Systemic illness | |||
| Rheumatoid arthritis | 20 (1.1) | 84 (4.7) | 4 to 6 |
| Flu | 13 (0.7) | ||
| Diabetes mellitus | 10 (0.6) | ||
| Malignancy | 10 (0.6) | ||
| Systemic lupus | 9 (0.5) | ||
| Eczema | 8 (0.5) | ||
| Organ failure | 6 (0.3) | ||
| Asthma | 5 (0.3) | ||
| GIT inflammatory diseases | 3 (0.2) | ||
| Mixed factors | 268 (15) | 13 to 17 | |
| Unknown cause | 341 (19.1) | 17 to 21 |
GIT, gastrointestinal tract.