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Intraoperative floppy iris syndrome (IFIS): Causes, characteristics and treatment

Depiction of a person with floppy iris syndrome

Intraoperative floppy iris syndrome (IFIS) is a type of small pupil syndrome that causes weak pupillary dilation and a stretchy iris. It poses a risk for complications that can occur during cataract surgery. These can include damage to the iris and pupil, inflammation and infection of the inside of the eye, and surgical wounds. 

IFIS can also cause tearing or displacement of other tissues in the eye, including the retina, lens capsule and vitreous humor

The condition was discovered in 2005. It is associated with the use of certain alpha-blockers. These are used to treat benign prostatic hyperplasia (enlarged prostate gland). IFIS can be mild, moderate or severe, and the intensity differs from patient to patient. 

Although IFIS can raise serious concerns for one’s eye health, experts consider the condition to be rare.

What causes floppy iris syndrome?

A loss of muscle tone in the iris (the colored part of the eye) can result in IFIS. Taking certain medications such as alpha-blockers can contribute to this decreased muscle tone. This then leads to complications in surgeries that take place near this part of the eye.

IFIS can be triggered by interactions with the following alpha-blockers. These are taken to treat a condition called benign prostatic hyperplasia (BPH) or for high blood pressure:

  • Alfuzosin (Uroxatral)

  • Tamsulosin (Flomax)

  • Terazosin (Hytrin)

  • Doxazosin (Cardura)

  • Silodosin (Rapaflo)

If you are a patient with BPH and you need cataract surgery, it’s very important to discuss the side effects of alpha-blockers. Ask your doctor how they can complicate your procedure.

IFIS is also more common in those with diabetes and Parkinson’s disease. The following conditions and their corresponding medications can also increase risk: 

  • Hair loss (finasteride)

  • High blood pressure (losartan, labetalol)

  • Restless leg syndrome (ropinirole)

  • Dementia (donepezil)

  • Anxiety (duloxetine)

Benzodiazepine sedatives, certain antipsychotics and the herbal supplement saw palmetto have also been associated with IFIS. However, IFIS is not as severe with these medications compared to the alpha-blockers for BPH.

How does tamsulosin (Flomax) affect cataract surgery?

Tamsulosin (Flomax) is the medication prescribed for most BPH patients. So it makes sense that Flomax is the most recognized when it comes to contracting IFIS during cataract surgery.

In fact, multiple studies have found that up to 90% of IFIS cases were caused by complications in those using Flomax at the time of their procedure.  

Additional data shows that the iris muscle tone can be as much as 23% thinner in patients who have taken or are taking tamsulosin. And this thinning of the iris muscle tone is a characteristic that contributes to the risk of IFIS. 

SEE RELATED: Eye problems? Medications may be the culprit 

Symptoms and features

IFIS has three key features that appear during cataract surgery. 

These include:

  • A floppy iris that ripples and moves excessively when fluids are injected into the eye during a procedure.

  • The pupil gradually getting smaller as the procedure progresses. The pupil is dilated before cataract surgery and a pupil that is too small makes it especially difficult to remove a cataract.

  • The tendency of the iris to fall out of place toward the incisions that were made at the beginning of the surgery.

Pupils also have difficulty dilating before surgery in many patients. The pupil margin can present with elasticity, and the whole iris will be of a weak consistency in structure due to poor muscle tone.  


If a person is at risk for IFIS, they may be at risk for a number of complications that can occur during cataract surgery. 

These complications can include:

Some problems can potentially be vision threatening. Speak with your doctor before surgery to address any concerns. 

SEE RELATED: What is a blown pupil? 

Can IFIS be prevented?

Simply stopping the use of tamsulosin or other medications that may cause IFIS before cataract surgery often does not prevent IFIS. On the contrary, there may be greater health risks caused by discontinuing the use of the medication.

Eye surgeons can take precautions before and during surgery to reduce the risk of IFIS, however. 

During surgery, the pupils need to remain dilated and the iris needs to be secured in place in order to prevent IFIS from occurring. There are several techniques for keeping the pupil dilated. These can include approaches like manually expanding the pupil with a special instrument and the use of certain drugs.

Many surgeons use instruments called iris retractors, iris hooks or expansion rings. These are installed through incisions before surgery, and removed at the end of the procedure. Each of these tools are designed to lift the iris tissue and keep the pupil dilated.

The iris hook/retractor method is considered the most reliable in preventing IFIS by experts.

Other methods for controlling or preventing IFIS may include:

  • Administering drugs such as preoperative atropine, intraoperative phenylephrine or an injection of epinephrine under the patient’s iris.

  • The use of viscoelastic fluids. These are designed to protect a layer of cells on the cornea called the corneal endothelium. They also help keep the front of the eye from collapsing during the surgery. These substances are injected during surgery, and additional doses may be needed in order to be effective.

While these options may help prevent IFIS, their success rate is not always guaranteed. The severity of IFIS varies greatly among patients, and the condition can be unpredictable in many cases.

Treatment and management

IFIS should be monitored by both an ophthalmologist and a urologist, as the disease involves the eyes and the prostate. 

While risks and complications are high for some, it’s important to remember that IFIS is rare. As of 2009, only 2% of cataract surgeries have resulted in the condition. 

Even so, precautions and education on the subject of IFIS are important for both the patient and medical providers to understand. If this is the case for you, don’t hesitate to ask your eye doctor and/or urologist about the risks and management of IFIS before receiving surgical treatment for cataracts.

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