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AAO  >  News  >  EyeNet  >  March 2005  >  News in Review  
News in Review
A Look at Today’s Ideas and Trends

Beware Floppy Iris During Phaco

Of the 16 million Americans aged 60 and older who have cataracts each year, a good many of them also have another common condition of aging: benign prostatic hypertrophy. More than 4 million times a year, elderly American men ask a doctor for help with BPH.

Recently two California ophthalmologists discovered that the BPH drug Floma (tamsulosin) causes iris complications during phacoemulsification. (Interestingly, Flomax is prescribed for some women with urinary retention.)

The pair’s peer-reviewed paper on what they call intraoperative floppy iris syndrome (IFIS) is being rushed into print this spring.1 And a January summary of their findings in a trade magazine sent cataract surgeons to online chat groups for advice on how to identify and deal with the condition.

Fortunately, authors David F. Chang, MD, of Los Altos, and John R. Campbell, MD, of San Rafael, had answers:

  • Ask patients before cataract surgery if they’re taking Flomax, and discontinue the drug for one to two weeks before surgery. This can lessen the iris’s floppiness, though not eliminate it, the authors found. Any prior history of Flomax use is important because IFIS cases can still occur in those who discontinued the drug as long as one to two years before cataract surgery.
  • Inquire about Flomax if the pupil dilates poorly at the time of surgery. “At that point, you still have time to modify your surgical plan,” said Dr. Chang. 
  • Common techniques such as mechanical pupil stretching or partial thickness sphincterotomies won’t work for IFIS, according to Dr. Chang. “The pupil will not expand and will still prolapse and progressively constrict during surgery.”
  • Disposable iris retractors or pupil expansion rings are the best way to maintain a larger pupil. Iris retractors should be placed in a diamond configuration, as described by Oetting and Omphroy in 2002.2

Drs. Chang and Campbell cautioned that iris prolapse by itself isn’t enough to denote IFIS. The syndrome is defined by a combination of three consistent characteristics: a floppy iris that billows in response to normal intraocular fluid currents, a strong propensity to iris prolapse and progressive miosis intraoperatively. “There are other causes of iris prolapse or of intraoperative miosis,” said Dr. Chang. “However, it is this triad of features that indicates that you are dealing with IFIS due to Flomax.”

Dr. Chang said he sees no need for urologists to stop prescribing Flomax for their patients with BPH at this time. “Iris retractors or other pupil expansion devices will assure a large pupil size throughout surgery in IFIS eyes,” he said. “Surgeons typically don’t use these devices for most small pupil cases because they are more expensive, time-consuming and harder to insert after the capsulorhexis has been created.” Other ophthalmologists have suggested using Healon 5 with low aspiration parameters.

“By knowing in advance when IFIS will occur, surgeons will be able to alter their usual method of small pupil management,” he said. “As long as ophthalmologists know how to anticipate and manage IFIS, there is no reason why Flomax patients shouldn’t have excellent results from cataract surgery.”

Dr. Chang is planning a multisurgeon prospective follow-up study to assess this prediction.

1 Chang, D. and J. Campbell. J Catact Refract Surg 2005; issue undetermined at EyeNet’s press time.
2 J Cataract Refract Surg 2002;28(4):596–598.

What Causes IFIS?

Flomax is the most uroselective of the alpha1-adrenergic receptor antagonists, which improve urine flow by relaxing smooth muscle in the prostate and bladder neck. For this reason, the drug long has been preferred because it decreases the risk of orthostatic hypotension in elderly men, said Dr. Chang.
There are three known alpha-1 receptor subtypes: A, B and D. Of the drugs in this class, including Hytrin (terazosin HCl) and Cardura (doxazosin mesylate), only Flomax is highly selective for the alpha1A subtype, which predominates in the prostate. The literature shows that alpha1A is also the main receptor subtype that mediates contraction of the iris dilator muscle in rabbits, said Dr. Chang. He and Dr. Campbell hypothesize that Flomax not only blocks the iris dilator muscle but also causes a semipermanent loss of muscle tone. This results in floppiness of the iris stroma that leads to billowing, prolapse and progressive miosis during cataract surgery. Some degree of dilator muscle atrophy would explain why IFIS still occurs in some patients who have been off Flomax for as long as two years. 


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