In a 1-day, 1-dose, double-masked, randomised trial, with each of 12 patients acting as his/her own control, atenolol drops 4% (a selective beta1-adrenergic blocker) produced a significantly greater fall in ocular tension measured by applanation than did adrenaline drops 1% (P is less than 0.01 Wilcoxon matched pairs signed ranks test). The mean differences, which favoured atenolol, between the...