Photo Credit: Todorean Gabriel

The following is a summary of “EFFECT OF TAMSULOSIN ON IRIS MORPHOLOGY, CILIARY MUSCLE THICKNESS, AND PUPIL DIAMETER,” published in the December 2024 issue of Ophthalmology by Öztürk et al. 

Researchers conducted a retrospective study to analyze the effect of tamsulosin on iris morphology, ciliary muscle thickness (CMT), pupil diameter (PD), and pupil responses to light using anterior segment optical coherence tomography and corneal topography.  

They included 43 patients’ right eyes with newly diagnosed benign prostatic hyperplasia. Measurements were taken for iris dilator muscle region (DMR) thickness, sphincter muscle region (SMR) thickness, DMR/SMR ratio, PD under scotopic, mesopic, and photopic light conditions, CMT at 3 locations (CMT1 at 1 mm, CMT2 at 2 mm, and CMT3 at 3 mm posterior to the scleral spur), and anterior chamber depth (ACD). These assessments were performed twice: before starting tamsulosin treatment and again at the 3-month follow-up.  

The results showed significant reductions in pre- and post-dilation iris DMR thickness (P <0.001), DMR/SMR ratio (P =0.001), and PD under photopic conditions (P =0.04) after tamsulosin treatment. Post-dilation PD decreased significantly (P <0.001). No significant changes were observed in iris SMR thickness (pre-dilation: P =0.08, post-dilation: P =0.784), CMT at CMT1, CMT2, and CMT3 (pre-dilation: P =0.841, 0.794, 0.880; post-dilation: P =0.367, 0.114, 0.256), pupil dilation speed (P =0.463), and anterior chamber depth (pre-dilation: P =0.583, post-dilation: P =0.305).  

Investigators concluded the tamsulosin treatment did not affect iris SMR thickness, CMT1, CMT2, CMT3, or ACD, but it significantly reduced iris DMR thickness, DMR/SMR ratio, pre-dilation photopic PD, and post-dilation PD. 

Source: ajo.com/article/S0002-9394(24)00569-5/abstract