The effects of two systemic α1-adrenergic blockers on pupil diameter: a prospective randomized single-blind study

Abstract

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.

The effects of systemic α1-adrenoreceptor antagonists on pupil diameter

“…There were similar findings under scotopic conditions, with study patients measuring 4.42 mm (OD) and 4.44 mm (OS), and control patients measuring 5.12 mm (OD) and 5.27 mm (OS) (p=0.0067 and p=0.0011). There have been similar findings published elsewhere 10. To look at these data in more detail, the study population was split into those who had taken α 1 -adrenoreceptor blockers for <2 years and those who had taken them for >2 years.…”

Stimulus Parameters for Multifocal Pupillographic Objective Perimetry

“…Brimonidine and treatments for benign prostatic hyperplasia, such as tamsulosin and alfuzosin, show effects on pupil size at low light levels but not at the levels used here. [43][44][45] Problems such as floppy iris syndrome may pose difficulties for mfPOP, however such conditions occur much less often than the rate at which patients currently fail perimetry examinations. [1][2][3][4] Overall, the present study indicates that mfPOP may be a viable adjunct to, or replacement for, SAP if further studies confirm the encouraging results seen here.…”

Influence of Tamsulosin on the Anterior Segment Parameters and Central Corneal Thickness

“…12,13 The effects of other α-1-adrenoreceptor antagonists regarding their effects on the iris are still under investigation. 14,15 Although there are various reports on the effect of tamsulosin on pupil diameter and iris morphology, there are no reports on the rest of anterior segment, central corneal thickness and corneal biomechanical changes.…”