The aim of the study was to identify if there is a connection between the time of administration of alpha-blocker medication and cataract surgery complications. Furthermore, it was explored whether discontinuation of tamsulosin before cataract surgery influences the manifestations of intraoperative floppy iris syndrome in rats. An experimental study was conducted on 20 male Wistar rats aged 1.5-2 years (body mean weight 357 g), which were divided into four equal groups: Group 1, under tamsulosin hydrochloride 0.4 mg/day for 2 months; group 2, without any treatment in the first month, followed by tamsulosin; group 3, under tamsulosin for 1 month, followed by 1 month without any treatment; and group 4, control. The pupillary diameter was assessed before instillation of 0.5% tropicamide (mydriatic and cycloplegic agent), after 1 or 2 h from instillation and postoperatively. Furthermore, pupil constriction during surgery, the presence of floppy iris and prolapse of the iris following the main incision and during serum injection were also assessed. Other analyzed features included iris rupture, posterior capsule tear, vitreous loss, lens fragments in the vitreous, suprachoroidal bleeding and corneal haze. The iris dilator muscle thickness and the posterior epithelium was measured using light microscopy. In the control group, the largest pupillary diameters were indicated and in group 1, the smallest pupillary diameters were revealed. Statistically significant differences were indicated between group 1 and 2 and group 3 and 4. Floppy iris, iris prolapse in the main incision and during serum injection appeared at maximum frequency for group 1 with continuous treatment and low frequency for the control group. Lens fragments in the vitreous were present in the groups 1-3. Notably, intraoperative miosis had statistical relevance in group 1 and group 2. To conclude, the present findings suggested there is a clear connection between the time of administration of the alpha-blocker medication and most cataract complications. The results indicated that discontinuation of tamsulosin for one month largely reduces the manifestations of intraoperative floppy iris syndrome in rats, which may suggest to change preoperative treatment for benign prostatic hypertrophy with another class of drugs that do not interact with the iris receptors.
Keywords: alpha-blocker; benign prostatic hyperplasia; cataract; floppy iris; tamsulosin.