The Effect of Systemic Tamsulosin Hydrochloride on Choroidal Thickness Measured by Enhanced Depth Imaging Spectral Domain Optical Coherence Tomography

Background: To evaluate the effects of selective alpha(1A)-adrenoceptor antagonist tamsulosin hydrochloride on choroidal thickness using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT). Methods: This is a prospective observational study including 29 eyes of 29 patients with newly diagnosed benign prostatic hyperplasia. Choroidal thickness and retrobulbar ocular blood flow measurements were performed at baseline and after 3 months of treatment. Results were analyzed by the masked observer. Results: The mean subfoveal choroidal thickness (275.8-291.9 mu m) and thicknesses 750 mu m nasal (257.9-270.4 mu m) and 750 mu m temporal (262.4-277.0 mu m) to the fovea were significantly increased after 3 months of treatment (p<0.001). No statistically significant change was found in retrobulbar ocular blood flow. Conclusions: Tamsulosin causes a significant increase in EDI-OCT-based choroidal thickness measurements. This increase might be associated with choroidal vasodilation in consequence of blockade of sympathetic alpha(1A)-adrenoceptors, which is critical for the maintenance of vascular tone and resistance in the choroidal vascular architecture. This should be kept in mind when choroidal disease and its response to treatment are followed by EDI-OCT imaging.