Table 2.

Mean differences in ocular itch scores post-CAC at 16 h after treatment instillation

Time point post-CAC	Difference in mean itch scores
	Alcaftadine versus placebo	Olopatadine versus placebo	Alcaftadine versus olopatadine
3 min	−1.57; P < 0.0001*	−1.20; P < 0.0001*	−0.37; P = 0.0006*
5 min	−1.45; P < 0.0001*	−1.26; P < 0.0001*	−0.19; P = 0.0873*
7 min	−1.17; P < 0.0001*	−1.14; P < 0.0001*	−0.03; P = 0.7751*
Over all time points	−1.42; P < 0.0001†	−1.19; P < 0.0001†	−0.24; P = 0.0390†

CAC conjunctival allergen challenge

* P values calculated using two-sample t test. ^† P values calculated using repeated measures analysis of covariance model accounting for treatment and time