Intraoperative floppy iris syndrome associated with tamsulosin

Complications of cataract surgery in patients with BPH treated with alpha 1A-blockers

The prevalence of benign prostate hyperplasia (BPH) and cataract increases with age. Both diseases may develop concomitantly and may affect almost 50% of elderly men as comorbidities. Cataract is treated surgically and it has been reported that there may be an association between use of alpha-blockers for BPH, particularly alpha1A-adrenergic receptor selective drugs, and complications of cataract surgery known as Intraoperative Floppy Iris Syndrome (IFIS). The article reviews literature published on this topic and provides recommendations on how to reduce incidence of iatrogenic IFIS or its severity and outcomes in patients with BPH.

Finasteride-associated cataract and intraoperative floppy-iris syndrome

A 47-year-old man who had been using finasteride for male pattern alopecia for 4 years complained of progressive bilateral blurring of vision. His general health had been good, and he was not on any other long-term medication. Examination showed bilateral anterior subcapsular cataracts. Phacoemulsification and insertion of intraocular lenses were performed, and both eyes showed features of intraoperative floppy-iris syndrome (IFIS), including undulation and billowing of the iris, iris prolapse, and pupil constriction. We believe the use of finasteride can be associated with cataract formation and IFIS. Ophthalmologists and physicians prescribing finasteride should be aware of this possible association.

FINANCIAL DISCLOSURE

Neither author has a financial or proprietary interest in any material or method mentioned.

Nepafenac-assisted mydriasis in a rabbit model

PURPOSE

To compare the effectiveness of nepafenac 0.10% in achieving and maintaining pupil dilation with the effectiveness of flurbiprofen 0.03% and a placebo in a rabbit model.

SETTING

Department of Ophthalmology, University of California, San Francisco, California, USA.

DESIGN

Laboratory study.

METHODS

Adult pigmented rabbits were randomized to 3 equal-sized groups: placebo, flurbiprofen, and nepafenac. Cataract surgery was performed in randomized order by a surgeon who was masked to group assignment. The treatment or placebo was administered starting 1 day before surgery. Phenylephrine 10.0% was administered starting 30 minutes before surgery. Phacoemulsification was performed in standard fashion. Pupil measurements were recorded before and after surgery. A linear mixed model with a random effect for the rabbits and a fixed effect for the treatment groups was used to compare mean pupil diameters between groups.

RESULTS

Baseline pupil measurements were similar between the placebo, flurbiprofen, and nepafenac groups. Preoperative pupil dilation was statistically significantly greater in the nepafenac group (mean 11.5 mm ± 0.5 [SD]) than in the placebo group (mean 10.2 ± 1.1 mm) and the flurbiprofen group (mean 9.9 ± 1.1 mm) (P<.005 and P<.001, respectively). The greater dilation was maintained at the end of surgery, at which time the nepafenac group had statistically significantly larger pupils (mean 9.4 ± 1.2 mm) than the placebo group (mean 7.9 ± 0.6 mm) and the flurbiprofen group (mean 8.5 ± 0.9 mm) (P<.001 and P<.05, respectively).

CONCLUSION

Nepafenac was more effective than a placebo and flurbiprofen in achieving maximum preoperative and postoperative pupil mydriasis in rabbits.

The effect of alpha1-adrenergic receptor antagonist tamsulosin (Flomax) on iris dilator smooth muscle anatomy

PURPOSE

To characterize and determine the effect of tamsulosin (Flomax) on the human iris dilator muscle anatomy.

DESIGN

Retrospective, case-control study.

PARTICIPANTS

This study comprised 51 cadaveric eyes from 27 patients (14 with a history of tamsulosin use and 13 control patients) who underwent autopsy at the Duke University Medical Center, Durham, North Carolina.

METHODS

Patients' records were reviewed, and age, medical, surgical, and ocular history; gender; medications; and duration and dosage of tamsulosin were recorded. Specimens were sectioned through the pupillary axis in the horizontal meridian and reviewed by light microscopy. A morphometric analysis was performed to measure the maximum and minimum iris dilator muscle thickness and the iris stromal thickness (micrometers) at 6 points in each eye. All microscopic evaluations and measurements were performed by the same masked observer.

MAIN OUTCOME MEASURES

To determine whether there is a significant difference in the iris dilator muscle or stromal thickness in those patients receiving tamsulosin treatment compared with age-matched controls.

RESULTS

The mean iris dilator muscle thickness in the tamsulosin-treated group (6.53+/-1.99 microm) was significantly thinner compared with that of the control group (8.50+/-1.61 microm) (P=0.006). There was no difference in iris stromal thickness between the 2 groups (P=0.268). There was no direct relationship between duration of tamsulosin use and iris dilator muscle or stromal thickness. Statistical significance was maintained when the iris dilator muscle thickness was compared between the groups using history of diabetes and cataract extraction as separate variables. No difference was noted when comparing the iris stromal thickness using diabetes as a separate variable. However, stromal thickness was significantly different between the groups in pseudophakic eyes (P=0.005).

CONCLUSIONS

According to histologic examination of cadaver eyes, patients receiving tamsulosin treatment exhibited decreased iris dilator muscle thickness compared with control patients. There was no difference noted in the iris stromal thickness within the groups. We believe this finding may shed light on the pathophysiology of intraoperative floppy iris syndrome. Further studies need to be performed to assess the significance of this histologic finding.

Lower lid entropion secondary to treatment with alpha-1a receptor antagonist: a case report

INTRODUCTION

The use of alpha-1a receptor antagonists (tamsulosin) is widely accepted in the treatment of benign prostatic hypertrophy (BPH). It has previously been implicated as a causative agent in intra-operative floppy iris syndrome due to its effects on the smooth muscle. We report a case of lower lid entropion that may be related to a patient commencing treatment of tamsulosin.

CASE PRESENTATION

A 74-year-old Caucasian man was started on alpha 1-a receptor antagonist (Tamsulosin) treatment for benign prostatic hypertrophy. Eight days later, he presented to the ophthalmology unit with a right lower lid entropion which was successfully treated surgically with a Weiss procedure.

CONCLUSION

We report a case of lower lid entropion that may be secondary to the recent use of an alpha-1a blocker (tamsulosin). This can be explained by considering the effect of autonomic blockade on alpha-1 receptors in the Muller's muscle on a patient that may already have an anatomical predisposition to entropion formation due to a further reduction in muscle tone.

The forefront for novel therapeutic agents based on the pathophysiology of lower urinary tract dysfunction: alpha-blockers in the treatment of male voiding dysfunction - how do they work and why do they differ in tolerability?

alpha(1)-Adrenoceptor antagonists are the mainstay of medical treatment of male voiding dysfunction which typically is attributed to benign prostatic hyperplasia. While original concepts have assumed that they relieve voiding dysfunction by relaxing prostatic smooth muscle, newer data indicate that their therapeutic effects at least partly occur independent of prostatic relaxation, perhaps involving direct effects on blood vessels, urothelium, afferent nerves, and/or smooth muscle of the urinary bladder. The adverse event profiles differ among alpha(1)-adrenoceptor antagonists, with tamsulosin having a particularly good cardiovascular tolerability. While this was originally attributed to its selectivity for alpha(1A)-adrenoceptors, it appears that alfuzosin which lacks subtype-selectivity, has a very similar tolerability. In contrast, doxazosin and terazosin, which are chemically and pharmacologically more closely related to alfuzosin than to tamsulosin, appear to have more side effects attributable to the cardiovascular system. More recent data indicate that tolerability differences between alpha(1)-adrenoceptor antagonists may at least partly relate to pharmacokinetic rather than to pharmacodynamic differences. Taken together, these data emphasize the idea that concepts about drug efficacy and tolerability despite being highly plausible may not necessarily be true and always require thorough experimental testing.

Silodosin for benign prostatic hyperplasia

OBJECTIVE

To review the pharmacology, pharmacokinetics, clinical trials, and safety of silodosin, a recently approved alpha(1A)-adrenergic receptor (AR) antagonist for benign prostatic hyperplasia (BPH).

DATA SOURCES

English-only articles obtained from MEDLINE (1966-October 2009) using the search terms silodosin and KMD-3213 were reviewed. In addition, a search of International Pharmaceutical Abstracts (1970-October 2009) was conducted.

STUDY SELECTION AND DATA EXTRACTION

Available English-language articles were reviewed, as well as abstracts from available non-English articles.

DATA SYNTHESIS

Silodosin reduces urinary symptoms associated with BPH in as little as 1 day after initiation. The largest clinical trial conducted to date demonstrated a decrease in International Prostate Symptom Score of -6.4 +/- 6.63 points compared to -3.5 +/- 5.84 in patients receiving placebo (p < 0.0001). Silodosin also improved urinary flow rates by approximately 2.8 +/- 3.44 mL/sec, which is comparable to other alpha(1)-AR antagonists. The usual dose of silodosin is 8 mg once daily and should be reduced to 4 mg for patients with moderate renal dysfunction. Use is contraindicated in patients with severe renal and hepatic impairment or taking strong CYP3A4 inhibitors. In clinical trials, the most prevalent adverse effects were ejaculatory disturbances, occurring in approximately 28% of patients, although only 2.8% of patients discontinued treatment due to this adverse effect. Preliminary data suggest that, similar to other third-generation alpha(1A)-AR antagonists, silodosin has little potential to cause significant cardiovascular adverse effects such as orthostatic hypotension or syncope. To confirm these findings, long-term studies are still needed, especially in patients taking antihypertensive agents and in those with a history of intolerance to other alpha(1)-AR antagonists.

CONCLUSIONS

Silodosin was approved by the Food and Drug Administration in 2008. Long-term studies demonstrating improvement in clinically important outcomes of BPH have yet to be published. In addition, pharmacoeconomic analyses would assist in defining its current place in therapy. Until this information is available, silodosin may be best reserved as an alternative to other second- and third-generation alpha(1)-AR antagonists.

Intraoperative floppy iris syndrome (IFIS): a practical approach to medical and surgical considerations in cataract extractions

Intraoperative floppy iris syndrome (IFIS) during cataract surgery is characterized by iris fluttering, iris prolapse towards the incisions, and a progressive pupillary constriction leading to high rates of complications. The syndrome has been reported following the treatment of benign prostatic hyperplasia with α-1(a) adrenergic receptor inhibitors, especially tamsulosin. The present paper describes the syndrome and discusses its pharmacological background. Several techniques to prevent and to deal with the syndrome are presented.

Management of benign prostatic hyperplasia with silodosin

It has been reported that blockade of α1A-adrenoceptor (AR) relieves bladder outlet obstruction, while blockade of α1D-AR is believed to alleviate storage symptoms due to detrusor overactivity. Silodosin, (-)-1-(3-hydroxypropyl)-5-[(2R)-2-({2-[2-(2,2,2trifluoroethoxy) phenoxy]ethyl}amino)propyl]-2,3-dihydro-1H-indole-7- carboxamide, is a new α1A-AR selective antagonist. Silodosin is highly selective for the α1A-AR subtype, showing an affinity for the α1A-AR that is 583- and 55.5-fold higher than its affinity for the α1B-and α1D-ARs, respectively. In randomized, double-blind, placebo-controlled phase III studies performed in Japan and the United States, silodosin has been shown to be effective for both storage and voiding symptoms associated with benign prostatic hyperplasia. Early effects of silodosin (after 2-6 hours or day 1) on lower urinary tract symptoms have also been reported. In urodynamic studies, detrusor overactivity disappeared in 40% and improved in 35% of patients after administration. In pressure flow studies, the grade of obstruction on the International Continence Society nomogram showed improvement in 56% of patients. The rate of adverse events in the silodosin, tamsulosin and placebo groups was 88.6%, 82.3%, and 71.6%, respectively. The most common adverse event was (mostly mild) abnormal ejaculation (28.1%). However, few patients (2.8%) discontinued silodosin because of abnormal ejaculation. Orthostatic hypotension showed a similar incidence in the silodosin (2.6%) and placebo (1.5%) groups. In conclusion, silodosin improves detrusor overactivity and obstruction and thus may be effective for both storage and voiding symptoms in patients with benign prostatic hyperplasia.

The Effects of Systemic Alpha-1 Adrenergic Antagonists on Pupil Diameter in Rats

PURPOSE

To investigate the effects of alpha-1 adrenergic blockers on pupil diameter (PD) in rats.

METHODS

Four groups, with 10 rats each, were designed to receive terazosin, tamsulosin, doxazosin, and no medication. Dilated pupil diameter (PD) measurements were performed 24 hr before, 24 hr after, and 30 days after the initiation of medication, and after 30 days of washout. The intergroup and intragroup differences in PD were evaluated using one-way ANOVA and Wilcoxon signed rank test, respectively.

RESULTS

In day 1, PD decreased in both eyes significantly only in tamsulosin and doxazosin groups, but these effects became insignificant at 30 days of treatment (p > 0.05). The control group showed no significant difference in PD (p > 0.05). PD values returned to baseline after the washout period in all groups.

CONCLUSIONS

A significant reduction in PD occurred in two of the three groups with alpha-1 adrenergic blockers (tamsulosin and doxazosin), but this effect was not sustained at 30 days. Further functional and structural studies of the iris are needed to determine the clinical significance of these findings.

Irrigating iris retractor for complicated cataract surgery

We describe an irrigating iris retractor for cataract surgery in eyes with small pupils. The retractor, a modified irrigating handpiece, has 2 standard side-port irrigating openings and a smooth, button-like iris hook in the front. The hook is inserted into the margin of a small pupil and retracts the pupil peripherally to allow visualization of cortical remnants in the equatorial area of the lens capsule. The capsule can then be safely cleaned using the aspirating handpiece in the surgeon's other hand.

Iris morphologic changes related to alpha(1)-adrenergic receptor antagonists implications for intraoperative floppy iris syndrome

PURPOSE

To identify iris structural alterations associated with intraoperative floppy iris syndrome (IFIS) in patients using systemic alpha(1)-adrenergic receptor antagonists (alpha-1ARA).

DESIGN

Cross-sectional study.

PARTICIPANTS AND CONTROLS

Twenty-nine patients with current or past treatment with any systemic alpha-1ARA and 22 untreated controls.

METHODS

Consecutive eligible patients underwent slit-lamp-adapted optical coherence tomography in a masked fashion under standardized lighting conditions.

MAIN OUTCOME MEASURES

Iris thickness at the dilator muscle region (DMR; measured at half of the distance between the scleral spur and the pupillary margin) and at the sphincter muscle region (SMR; 0.75 mm from the pupillary margin), the ratio between the DMR/SMR (to compensate for possible intersubject variability), and pupillary diameter.

RESULTS

Most treated patients were on tamsulosin (27/29). Mean age was similar in study and control groups (70.6+/-7.6 vs 67.1+/-9.1 years; P = 0.061). Photopic pupil diameter was reduced in the study group (2.06+/-0.5 vs 2.5+/-0.6 mm; P = 0.001). The SMR was similar between groups (P = 0.53). Significantly lower values were found in treated subjects for the DMR and the DMR/SMR ratio (P<0.001). These differences remained significant after adjusting for pupil diameter (P<0.001). Multiple regression analysis showed that a longer duration of alpha-1ARA treatment correlated to a reduced DMR/SMR ratio (P = 0.001; r = 0.47). Age and eye color were not significant in this model.

CONCLUSIONS

Patients using systemic alpha-1ARA have significantly lower values of DMR thickness and DMR/SMR ratio and smaller pupil diameter when compared with age-matched controls. These differences seem to be related to the duration of drug exposure and provide evidence of structural alterations to the iris dilator muscle from this class of agents in IFIS.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Incidence, clinical findings and management of intraoperative floppy iris syndrome associated with tamsulosin

PURPOSE

To determine the risk ratios and incidence of intraoperative floppy iris syndrome (IFIS) during cataract surgery in patients using tamsulosin, and to assess management strategies for IFIS.

METHODS

We performed a non-randomized, observational, prospective study, in which 594 eyes of 579 patients undergoing cataract surgery were enrolled. Surgeons were masked to the patients' drug history. Usage or non-usage of tamsulosin, duration of tamsulosin use, presence or absence of IFIS, management of IFIS and intraoperative complications were recorded in the patients' theatre notes.

RESULTS

Twelve of 15 (80%) IFIS patients were taking systemic tamsulosin. Twelve of 23 (52%) patients using tamsulosin showed features of IFIS. The odds ratios (ORs) and relative risk (RR) ratios show strong positive correlations between tamsulosin use and IFIS. The ORs and RR ratios and the 95% confidence intervals (CIs) are as follows: OR 206.5 (95% CI 50.9-836.5); RR 99.3 (95% CI 30.0-327.8). There were no statistically significant differences between patients with or without IFIS, who were using tamsulosin, in terms of age or duration of tamsulosin use (p > 0.05). Seven eyes (46.6%) with IFIS were successfully managed with epinephrine. Eight eyes (53.4%) with IFIS needed iris hooks.

CONCLUSIONS

Patients using tamsulosin appear to be at high risk of IFIS during cataract surgery. The occurrence of IFIS may not be affected by duration of tamsulosin use or age. Epinephrine may be effective in approximately 50% of eyes with IFIS. The iris hook procedure represents an effective management strategy in IFIS.

[Treatment of LUTS in BPS. When and when not to administer pills?]

Benign prostatic syndrome (BPS) is considered a diagnosis of exclusion and needs a thorough work-up. One of the pitfalls for a tailored medical treatment scheme is the objective evaluation of benign prostatic obstruction. Characteristics of the various medical therapy options and the multifactorial origin of LUTS in BPH patients imply an individualized approach. LUTS involving mostly urine storage disorders and a small prostate are suitably managed with alpha(1)-receptor antagonists, which may be combined with antimuscarinics if OAB symptoms predominate. Long-term treatment addressing clinical progression may favor combination therapy of alpha(1)-receptor antagonists with 5alpha-reductase inhibitors if prostate size is sufficient. Age, symptom severity at baseline, a large prostate volume, or a high PSA value are indicative of progression. However, combination therapy aggravates side effects, and thus a risk-benefit analysis is essential. The potential of any medication for BPS to treat obstruction is rather low. If deobstruction is the main aim of therapy, medical treatment is not suitable.

α-Blockers in Benign Prostatic Hyperplasia: The Problem of “Floppy Iris Syndrome”. Results of a Case-Control Study to Evaluate the Surgical Risk through the Meausurement of Pupil Diameter

Objectives

α-blockers are a group of α-adrenoceptor antagonists used by urologists to treat lower urinary tract symptoms suggestive of benign prostatic hyperplasia. Recent studies have suggested that these drugs – tamsulosin in particular – are involved in the development of iris complications during phacoemulsification. The objective of this study is to investigate the effects of α-blockers – especially tamsulosin – on pupil diameter.

Materials and Methods

We measured the photopic, mesopic and post-dilatation pupil diameters in both eyes of 24 patients (46 eyes in total), 16 of them treated with α-blockers and 8 of them (16 eyes in total) not treated with any drugs (controls).

Results

All patients treated with tamsulosin showed minor photopic, mesopic and post-dilatation diameters compared to controls. Patients treated with other α-blockers did not show any difference compared to controls.

Conclusions

Even if a small number of eyes was evaluated, our study shows that tamsulosin - through its selective effect on α1A receptors - is the most involved drug in the Intraoperative Floppy Iris Syndrome.

Medical therapy options for aging men with benign prostatic hyperplasia: focus on alfuzosin 10 mg once daily

Lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) are common in aging men and can significantly affect quality of life. Men with bothersome LUTS/BPH often present with various other age-related conditions, including sexual dysfunction, heart disease, hypertension, diabetes, and the metabolic syndrome, which can complicate management decisions. Therefore, healthcare providers should be familiar with first-line treatment options for LUTS/BPH and their differing safety profiles, particularly with respect to cardiovascular and sexual function side effects. This article presents a review of first-line medical therapy options for managing aging men with LUTS/BPH and patient considerations when evaluating and selecting these therapies, with a focus on the clinical efficacy and cardiovascular and sexual function safety profiles of the uroselective alpha1-adrenergic receptor antagonist alfuzosin 10 mg once daily. Alfuzosin improves LUTS, peak urinary flow rates, and disease-specific quality of life, reduces the long-term risk of overall BPH progression, and is well tolerated in aging men, with minimal vasodilatory and sexual function side effects, even in those with comorbidities. Alfuzosin is well tolerated when used in combination with antihypertensive medications and phosphodiesterase type 5 inhibitors for the treatment of erectile dysfunction. The long-term clinical efficacy and good cardiovascular and sexual function safety profile of alfuzosin can contribute to an improved quality of life for aging men with LUTS/BPH.