Anterior segment morphologic changes related to α-1 adrenergic receptor antagonists use

The Effect of Tamsulosin on Iris Morphology, Ciliary Muscle Thickness, and Pupil Diameter

PURPOSE

To investigate 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.

DESIGN

Prospective clinical before-and-after study METHODS: The right eyes of 43 patients with newly diagnosed benign prostatic hyperplasia were included in this study. Iris dilator muscle region (DMR) thickness, sphincter muscle region (SMR) thickness, DMR/SMR ratio, PD (scotopic, mesopic and photopic light conditions), CMT1 (1 mm posterior to the scleral spur), CMT2 (2 mm posterior to the scleral spur), CMT3 (3 mm posterior to the scleral spur) and anterior chamber depth (ACD) were measured before and after dilation. Measurements were performed twice firstly before starting tamsulosin treatment and secondly at the 3rd month of tamsulosin treatment.

RESULTS

Pre-dilation DMR thickness (P < .001), post-dilation DMR thickness (P < .001) pre-dilation DMR/SMR ratio (P = .001), and post-dilation DMR/SMR ratio (P = .001) were reduced significantly after tamsulosin treatment. Pre-dilation PD decreased after treatment in scotopic, mesopic and photopic conditions, but only photopic conditions showed a significant difference (P = .733, P = .142, and P = .04, respectively). Post-dilation PD was significantly reduced after tamsulosin treatment (P < .001). No significant differences were found in pre- and post-dilation iris SMR thickness (P = .08 and P = .784, respectively), pre-dilation CMT1, CMT2, and CMT3 (P = .841, 0.794, 0.880, respectively), post-dilation CMT1, CMT2, and CMT3 (P = .367, 0.114, 0.256, respectively), pupil dilation speed (P = .463), pre-dilation ACD (P = .583), and post-dilation ACD(P = .305) after treatment.

CONCLUSION

Tamsulosin treatment does not change the iris SMR thickness, CMT1, CMT2, CMT3, and ACD but statistically significantly reduces the iris DMR thickness, DMR/SMR ratio, pre-dilation photopic PD, and post-dilation PD.

Effects of systemic fingolimod treatment on anterior segment parameters and tear film functions

PURPOSE

To investigate the potential effects of systemic fingolimod treatment on parameters of the anterior segment of the eye and tear film function tests in patients with multiple sclerosis (MS).

METHODS

Forty-eight eyes of 24 individuals who were started on systemic fingolimod treatment for relapsing-remitting MS were prospectively enrolled in this study. Patients underwent examinations immediately before initiation of systemic fingolimod treatment, and at the first and sixth months of treatment. Anterior segment parameters were measured using Sirius Topography. The Schirmer-I test and tear break-up time (TBUT) were recorded during follow-up. Retinal thickness was also analyzed using spectral-domain optical coherence tomography (SD-OCT).

RESULTS

There was no statistically significant difference in retinal thickness measurements between follow-up visits. The central corneal thickness, keratometric values, anterior chamber depth, aqueous humor depth, iridocorneal angle, horizontal anterior chamber tilt and anterior chamber volume values remained similar during follow-up. The Schirmer-I test value was 15.10 ± 2.65 mm at the zeroth month and 17.03 ± 3.61 mm at the sixth month (p = 0.044). The mean TBUT was significantly higher at the six-month visit compared to baseline and the one-month visit (p0-6 < 0.001, p1-6 < 0.001), but there was no statistically significant difference between baseline and month 1 (p0-1 = 0.419).

CONCLUSION

Systemic use of fingolimod may increase Schirmer I test and TBUT values in MS patients without altering other anterior segment parameters within 6 months.

Risk of intraoperative floppy iris syndrome among selective alpha-1 blockers—A consistency model of 6,488 cases

Selective α1-blockers are commonly administered to patients with lower urinary tract syndrome and benign prostatic hyperplasia, but may increase the risk of intraoperative floppy iris syndrome (IFIS). The purpose of this study aimed to clarify the risk of IFIS among various selective α1-blockers. Four databases were searched for prospective studies comparing alpha-1-antagonists. Data were pooled using the consistency model, and used risk ratio (RR) and mean difference (MD) for IFIS and pupil diameter, respectively. This study finally included 25 prospective comparative studies. Based on 51 direct comparisons with 6488 cases, risks of IFIS in patients who received tamsulosin [RR, 13.85; 95% confidence interval (CI): 7.34 to 26.11], terazosin (RR, 8.94; 95% CI 2.88 to 27.74), alfuzosin (RR, 7.73; 95% CI: 3.05 to 19.62), and doxazosin (RR, 3.88; 95% CI: 1.13 to 13.28) were significantly higher than those did not receive α1-antagonists. Based on 11 direct comparisons with 564 cases, as compared to no α1-antagonists, patients who received tamsulosin (MD, −0.36; 95% CI: −0.71 to −0.01) and alfuzosin (MD, −0.34; 95% CI: −0.62 to −0.07) showed smaller pupil diameter under mesopic light levels, while those received silodosin did not show significantly smaller mesopic pupil diameter than people without α1-antagonists. IFIS seems to be inevitable with the usage of α1-antagonists, and tamsulosin needs to be cautious due to the significantly higher risk of severe IFIS. With regard to silodosin, there is no strong evidence to support the uses of italthough it does not significantly decrease mesopic pupil diameter.

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.