Effect of tamsulosin on iris vasculature and morphology.

Purpose: To determine whether preoperative iris vasculature and morphology are altered in patients who have taken tamsulosin (Flomax).

Setting: Academic multispecialty practice.

Design: Case series.

Methods: Patients with current or past tamsulosin use and age- and sex-matched control patients were included. Anterior segment optical coherence tomography (AS-OCT) and iris fluorescein angiography were performed to measure iris vasculature and thickness before cataract surgery. Data collected at surgery included pupil diameter, clinical signs of intraoperative floppy-iris syndrome, and surgical complications.

Results: Tamsulosin was currently used by 16 patients and in the past by 4 patients; the control group comprised 10 patients. Pharmacologically dilated pupil diameter was statistically significantly smaller preoperatively and immediately postoperatively in the tamsulosin group than in the control group (P=.009 and P=.003, respectively). There was a statistically significant decrease in pupil size intraoperatively in the tamsulosin group (P=.05) but not in the control group (P=.3). Iris-vasculature parameters, specifically time to first vessel fill and percentage of vessel fill on iris fluorescein angiography, were not significantly different between the 2 groups. The AS-OCT measurements of iris morphology were not statistically significantly different between the groups. No surgical complications occurred. No fluorescein dye leakage, staining, or other vascular anomalies were observed.

Conclusions: Although there were differences in pupil measurements and intraoperative iris behavior between patients who had been on tamsulosin and control patients, there were no significant differences in iris vasculature on iris fluorescein angiography or in iris morphology on AS-OCT.