The effects of two systemic alpha1-adrenergic blockers on pupil diameter: a prospective randomized single-blind study.

Our aim was to investigate the effects of two alpha(1)-adrenergic blockers-tamsulosin and alfuzosin-on pupil diameter (PD). In this prospective randomized single-blind clinical trial, 64 patients with benign prostatic hyperplasia received treatment with either tamsulosin or alfuzosin. The same ophthalmologist, masked to the given medication, evaluated patients prior to, 4 weeks after and 6 months after the start of the medication (day 0, day 28 and month 6). Best corrected visual acuity and PD under mesopic, scotopic, and dilated conditions were measured. t-test, ANOVA, and Dunnett's multiple comparison post-test were used for statistical analysis. With tamsulosin treatment, both mesopic and scotopic PD decreased, respectively, from 3.9 +/- 0.7 and 5.7 +/- 0.6 mm at day 0 to 3.6 +/- 0.9 and 5.5 +/- 0.8 mm at day 28, and 3.6 +/- 0.7 and 5.4 +/- 0.7 mm at month 6 (ANOVA; P = 0.021 and = 0.040, respectively). However, the difference in dilated PD was not significant (day 0 7.8 +/- 0.6 mm, day 28 7.7 +/- 0.7 mm, and month 6 7.6 +/- 0.6 mm, P = 0.379). In the alfuzosin group, PD did not differ significantly from the baseline except for the scotopic measurements, which decreased from 5.6 +/- 0.6 mm at day 0 to 5.5 +/- 0.6 mm at day 28 and 5.2 +/- 0.8 mm at month 6 (P = 0.004). Compared to baseline values, small but statistically significant decreases were detected in mesopic and scotopic illumination in patients treated with tamsulosin and in scotopic PD in patients treated with alfuzosin. The clinical significance of these differences needs further evaluation.