Frequency of symptoms reported by patients treated with preserved and preservative free eye drops at the first visit
| Preserved eye drops (n=3469) | Preservative free eye drops (n=552) | |
|---|---|---|
| *Preservative free versus preserved comparison: p<0.001 (χ2 test). | ||
| Discomfort upon instillation | 43% | 17%* |
| Foreign body sensation | 31% | 14%* |
| Stinging or burning sensation | 40% | 22%* |
| Dry eye sensation | 23% | 14%* |
| Tearing | 21% | 14%* |
| Eyelid itching | 18% | 10%* |
| Presence of symptoms of irritation between instillations | 61% | 36%* |