Floppy Iris Syndrome :
what you need to know before cataract surgery
A known side effect of certain prostate medications — essential to disclose before your cataract surgery.
What is Intraoperative Floppy Iris Syndrome ?
Intraoperative Floppy Iris Syndrome (abbreviated as IFIS) describes a specific reaction of the iris — the colored part of your eye — during cataract surgery. In affected patients, the iris becomes abnormally soft and unstable during surgery : it may deform, fold over, or interfere with the surgeon’s instruments.
This phenomenon causes no symptoms in everyday life. It only occurs during surgery and affects only patients who take or have taken certain specific medications. It was first described in 2005 by American ophthalmologists Chang and Campbell.
Which medications are responsible ?
The medications most commonly involved are alpha-blockers, usually prescribed for benign prostatic hyperplasia — a non-cancerous enlargement of the prostate that is very common in men over 50.
Tamsulosin : the most strongly implicated molecule
Tamsulosin is most closely associated with floppy iris syndrome. It is marketed under several brand and generic names and is widely prescribed worldwide.
Other alpha-blockers
Other molecules in the same family (alfuzosin, terazosin, doxazosin, silodosin…) can also trigger floppy iris syndrome, although the effect appears less pronounced than with tamsulosin.
Beyond alpha-blockers
More recent studies have identified other medication classes that can also trigger floppy iris syndrome, less commonly than alpha-blockers but well documented : tricyclic antidepressants (notably imipramine), certain antipsychotics (chlorpromazine, risperidone), 5-alpha reductase inhibitors (finasteride, dutasteride — used for prostate and hair loss), certain glaucoma eye drops (brinzolamide) and inhaled bronchodilators (salbutamol). The common mechanism is an indirect influence on iris tone.
How do these medications work ?
These medications relax smooth muscle, improving urinary comfort in men with prostatic hyperplasia. However, they also act on the muscle fibers of the iris, which can leave it floppy for a prolonged or even permanent period.
Why is it a concern during surgery ?
During cataract surgery, the surgeon needs the pupil to remain well-dilated in order to access the opacified lens and replace it with an implant. In patients with floppy iris syndrome, three phenomena can complicate the procedure :
The pupil constricts spontaneously during surgery. The surgeon loses visibility on the lens.
The iris ripples with fluid movements inside the eye, making it difficult to preserve during lens aspiration.
The iris can engage in the instruments or be damaged by prolapsing through the small corneal incision.
Without preparation, this instability increases the risk of intraoperative complications (capsule rupture, iris damage). That is why it is essential to disclose — even past — intake of these medications before surgery.
How the surgeon handles the situation
Once informed, Dr Gozlan has several effective options to secure the surgery. The technique is adapted case by case based on the intensity of the syndrome.
Tighter incision construction
The incisions made at the start of surgery are constructed in a specific way to prevent the iris from easily prolapsing during the procedure.
Injection of specific viscoelastic agents
Particularly « cohesive » viscoelastic gels are injected to mechanically stabilize the iris and keep the surgical space open.
Malyugin ring placement
A small circular ring is placed in the pupil to keep it mechanically open throughout the procedure. This is currently the most widely used solution.
Iris hooks
In some cases, small hooks are inserted through micro-incisions to anchor the edges of the iris and prevent it from engaging in the instruments.
Adjustment of phaco settings
Ultrasound parameters and irrigation flow are adjusted to limit fluid movements that cause iris billowing.
With these techniques, surgery can be performed safely even on a very floppy iris. The risk of complications returns to a level close to that of standard surgery, provided the surgeon is informed in advance.
What to do if you are concerned ?
Disclose it to the surgeon at the preoperative consultation. This information changes the surgical preparation (specific equipment, adapted technique) but in no way contraindicates cataract surgery.
What information to provide
The exact name of the medication (bring your box or prescription), the dose, the start date, and the stop date if you no longer take it.
Even past treatment must be disclosed
If you took an alpha-blocker several years ago, disclose it anyway. The effect on the iris persists long after stopping the medication.
Should the treatment be stopped before surgery ?
No. The effect of these medications on the iris is permanent : once exposed, the iris remains sensitive even after several years off the drug. There is therefore no benefit in stopping the medication before cataract surgery.
Moreover, these treatments have a specific medical indication (urinary discomfort, prostatic hyperplasia). Unsupervised discontinuation can have unpleasant urinary consequences. Any change to your treatment must be discussed with your urologist or general practitioner, not decided in view of cataract surgery.
Frequently asked questions
No, provided it is anticipated. Once informed, the surgeon adapts the technique and the complication risk drops to a level close to standard surgery.
Approximately 1 to 2 % of cataract surgeries. The syndrome predominantly affects men over 60 treated for their prostate.
No. The effect on the iris is permanent and stopping the medication provides no benefit. Any treatment change must be discussed with your urologist.
The effect is permanent : it persists even after several years off the drug. That is why even past use of these medications must always be disclosed.
Yes. It is more common in men (due to prostate treatments), but it also affects women. Several medications commonly used by female patients can trigger the syndrome : certain glaucoma eye drops (brinzolamide), inhaled bronchodilators (salbutamol), tricyclic antidepressants, or alpha-blockers prescribed for urinary issues. That is why it is important for every female patient — as for every male patient — to provide a complete list of medications at the preoperative consultation.
It is not mandatory, but it is useful to mention the planned surgery to your urologist or GP. The ophthalmologist handles the adaptation of the surgical technique.
References & medical sources
- Chang DF, Campbell JR. Intraoperative floppy iris syndrome associated with tamsulosin. J Cataract Refract Surg. 2005;31(4):664–673.
- Chang DF, Braga-Mele R, Mamalis N, et al. Clinical experience with intraoperative floppy iris syndrome : results of the 2008 ASCRS member survey. J Cataract Refract Surg. 2008;34(7):1201–1209.
- European Society of Cataract & Refractive Surgeons (ESCRS). Guidelines for the management of IFIS in cataract surgery. 2023.
- Haute Autorité de Santé (HAS). Chirurgie de la cataracte chez l’adulte. Paris : HAS ; 2023.
- Lakhani M, Kwan ATH, Mihalache A, Popovic MM, Hurley B, Muni RH. Drugs associated with floppy iris syndrome : a real-world population-based study. Am J Ophthalmol. 2025. doi:10.1016/j.ajo.2025.03.023
- American Academy of Ophthalmology. Real-world study of drugs linked to floppy iris syndrome. EyeNet Magazine. 2025.