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
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
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
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
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.