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

OBJECTIVES: To evaluate and compare anterior segment changes in patients taking alpha-1 (α1) blockers (tamsulosin, terazosin, doxazosin, alfuzosin) for benign prostatic hypertrophy, during drug intake and drug-free period, using ultrasound biomicroscopy (UBM). MATERIALS AND METHODS: In this prospective study, UBM was done before and after pupil dilatation in 31 phakic eyes of 19 male patients taking α1-blockers. Undilated and dilated UBM was repeated before cataract extraction, after stopping the drug for 10 days. On ideal images, pupil diameter (PD), anterior chamber depth (ACD), anterior chamber angle (ACA), and angle opening distances at points 500 µm and 250 µm from the scleral spur (AOD500 and AOD250) values were noted and changes in parameters were evaluated to reveal any changes that occurred after discontinuing the drug. No patient in the study was previously or currently using any other α1-adrenergic antagonist medication. Exclusion criteria for all patients included a history of diabetes mellitus, systemic hypertension, glaucoma, pseudoexfoliation syndrome, chronic use of medicated eye drops, and previous ocular surgery. RESULTS: PD, ACD, ACA, AOD500 and AOD250 values measured before pupil dilatation in the drug-free period were not significantly different from those measured during α-blocker intake (p>0.05). In dilated eyes, the mean value of AOD500 was 0.35±0.08 mm during drug usage and 0.39±0.08 mm in the drug-free period. The mean value of AOD250 was 0.23±0.06 mm during drug usage and 0.26±0.07 mm after discontinuation. These increments were statistically significant (p<0.05, z=-3.699, z=-2.984). On the other hand, there were no significant differences in ACD, ACA, or PD values in dilated eyes after discontinuing α1-blockers (p>0.05). CONCLUSION: The interruption of taking α1-blockers in patients who have benign prostatic hypertrophy does not seem to influence anterior segment parameters generally. However, further investigation is needed.