Iris damage caused by intraoperative floppy iris syndrome and iris prolapse.
The American Society of Cataract and Refractive Surgery (ASCRS) and the American Academy of Ophthalmology have issued an educational update(ascrs.org) about cataract surgery complications associated with use of systemic alpha blockers. According to a joint news release(www.aao.org) from the organizations, the update is being released in concert with two studies published this month.
The good news is family physicians can play a role in reducing the likelihood of these adverse events by ensuring that patients who take these drugs know the importance of notifying their ophthalmologist before the eye procedure is performed.
One of the most commonly performed surgeries in the United States, more than 3 million cataract procedures are performed each year. Alpha blockers, which relax the smooth muscle of the prostate and bladder wall, are the medications most frequently prescribed to treat the lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH). However, said the release, because these drugs also inhibit and disable the iris dilator muscle, alpha blockers often complicate cataract surgery by causing sudden intraoperative iris prolapse and pupil constriction, known as intraoperative floppy iris syndrome (IFIS).
- The American Society of Cataract and Refractive Surgery and the American Academy of Ophthalmology issued an educational update about intraoperative floppy iris syndrome (IFIS) associated with patients' use of systemic alpha blockers in conjunction with the release of two new studies.
- One study compared the relative frequency and severity of IFIS with use of tamsulosin versus alfuzosin and found that tamsulosin was more likely to cause severe IFIS.
- The second study offered results from a recent survey of primary care physicians that showed about 35 percent of the physicians reported knowing about alpha blockers affecting cataract surgery.
"Considering the prevalence of both cataracts and benign prostatic hyperplasia, many ophthalmologists worry about the increasing numbers of challenging IFIS cases as our population ages," said David Chang, M.D., immediate past president of ASCRS, in the joint news release. "Managing the side effects and complex interactions of a lengthy medication list is challenging. We welcome the opportunity to be a resource for physicians who prescribe alpha blockers in an effort to reduce cataract surgery complications for our mutual patients."
Tamsulosin (Flomax), in particular, is selective for the alpha-1A receptor that predominates in both the iris dilator muscle and prostatic smooth muscle. Although all alpha blockers can impair pupil dilation and cause IFIS, the bulk of available evidence(www.aaojournal.org) indicates that tamsulosin is more likely to cause severe IFIS than nonselective blockers such as terazosin (Hytrin), doxazosin (Cardura) and alfuzosin (Uroxatral), according to the release.
One recent study further strengthens this argument.
Published in the April issue of Ophthalmology, the prospective, multicenter study(www.aaojournal.org) compared the relative frequency and severity of IFIS with use of tamsulosin versus that seen with use of alfuzosin. Use of intracameral phenylephrine or epinephrine was not permitted among study participants. In a masked comparison of 226 eyes enrolled, 34.3 percent of eyes exposed to tamsulosin developed severe IFIS versus 16.3 percent of eyes exposed to alfuzosin and 4.4 percent of eyes in the control group.
A second study suggests more work needs to be done to ensure that all prescribers of alpha blockers get the message that these drugs can complicate cataract surgery. According to the results of a survey involving family physicians and other primary care clinicians(www.jcrsjournal.org) that was published in the April issue of the Journal of Cataract and Refractive Surgery, about 35 percent of those surveyed knew that alpha blocker use could affect cataract surgery, and about half of that group factored this into treatment considerations. The vast majority of survey respondents -- 96 percent -- desired more information on the association between the two factors.
Chang told AAFP News that he encourages family physicians who are about to initiate nonemergent alpha-1 antagonist treatment for BPH (or other indications) to ask the patient about any planned or possible cataract surgery. "If he has already had both cataracts removed, then there is no need to avoid or worry about any alpha-1 antagonist," said Chang. "If the patient says he has a cataract and also his vision has been getting worse, then he may want to have an eye exam to see if cataract surgery is a consideration before starting on chronic alpha-1 antagonist treatment."
Alternatively, said Chang, if there is a history of early cataract, but surgery is not yet needed, starting with a nonselective alpha-1 antagonist (i.e., alfuzosin, terazosin or doxazosin) may be preferable. If the nonselective drug is ineffective, however, tamsulosin use need not be discouraged.
What's most important, according to Chang, is to remind patients to tell their ophthalmologist about the alpha-1 antagonist prior to having any eye surgery. "Cataract surgery will still have an excellent prognosis," he noted, "but it may be more complex if they have taken the drug, and the surgeon should be forewarned so that additional measures can be taken."
More From AAFP
American Family Physician: "Floppy Iris Syndrome: Why BPH Treatment Can Complicate Cataract Surgery"
(June 15, 2009)
BMJ: "Benign prostatic hyperplasia: α1 adrenoreceptor antagonists and cataract surgery"(www.bmj.com)
(Feb. 7, 2008)
FDA MedWatch Safety Alert: Flomax (tamsulosin HCl)(www.fda.gov)
(Nov. 22, 2005)