Table 2: Frequency of symptoms reported by patients with preserved and preservative-free eyedrops at first visit³³

		Preserved eyedrops (n = 3469)		Preservative-free eyedrops (n = 552)
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%

*Preservative-free vs preserved comparison: p < 0.001 (χ²-test)