Effect of tamsulosin on iris vasculature and morphology

Abstract

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 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.

Clinical risk factors associated with intraoperative floppy iris syndrome: a prospective study

“…Additionally, in vitro rabbit studies revealed that tamsulosin binds to melanin in the iris, causing atrophy of the dilator muscle, which could be a second mechanism leading to IFIS [18]. Alpha1A-ARs are also the most widespread adrenergic receptors in the arterioles of the iris, but a previous study using iris fluorescein angiography and anterior segment optical coherence tomography (AS-OCT) did not find evidence that tamsulosin use may lead to dysregulation of the iris vessels [19].…”

Evaluation of Anterior Segment Changes of Patients Taking Alpha1-Blockers by Ultrasound Biomicroscopy in the Drug-free Period

“…Although some other studies using AS-OCT describe changes in iris thickness associated with tamsulosin use in patients with glaucoma, 8 similar to Tufan et al, 15 they did not detect differences in iris thickness in their study. In contrast to the differences in pupil size seen by Tufan et al 15 on AS-OCT, Shtein et al 14 found that photopic pupil measurements on AS-OCT were not significantly different between patients who had taken tamsulosin and those who had not. Their clinical measurements of pharmacologically dilated pupil size before surgery found significantly smaller pupils in patients who had used tamsulosin than in control patients, in contrast to the findings in a study by Cooney et al 16 They believed that their study used stronger pharmacologic pupil dilators because patients were being prepared for surgery rather than being dilated in the clinic.…”

“…Shtein et al 14 used AS optical coherence tomography (AS-OCT) to assess iris morphology, including iris thickness and PD in patients using tamsulosin. Although some other studies using AS-OCT describe changes in iris thickness associated with tamsulosin use in patients with glaucoma, 8 similar to Tufan et al, 15 they did not detect differences in iris thickness in their study.…”

Anterior Segment Optical Coherence Tomography Analysis of Iris Morphometric Changes Induced by Prostaglandin Analogues Treatment in Patients with Primary Open Angle Glaucoma or Ocular Hypertension

“…Pathogenesis of Intraoperative Floppy Iris Syndrome (IFIS) seems to be related to progressive loss of iris muscle tone caused by atrophy of iris dilator muscle [ 36 , 37 ].…”