ASCRS (American Society of Cataract and Refractive Surgery) Issues Physician Advisory on Flomax®
Evidence Suggests Link Between Drug and Intraoperative Iris Complications
Two separate prospective and retrospective studies totaling more than 1600 combined patients sought to characterize the features, the incidence, the cause, and the management of a new small pupil syndrome that they have named the Intraoperative Floppy Iris Syndrome (IFIS). The results of the studies have been submitted for publication in the Journal of Cataract & Refractive Surgery, and will also be reported at the ASCRS Symposium in April in San Francisco.
As quoted from the EyeWorld article, â€œwe found overwhelming evidence that IFIS is associated with the use of tamsulosin (Flomax®), a systemic alpha-1 antagonist medication. This drug relaxes the smooth muscle in the bladder neck and prostate, improving urinary flow in patients with symptomatic benign prostatic hypertrophy (BPH). Flomax is highly selective for the alpha-1A receptor subtype that predominates in the prostate. It is therefore more uroselective compared to other alpha-1 blockers for BPH, such as Hytrin and Cardura. For this reason, it is currently the most commonly prescribed medication for BPH. Interestingly, we did not find that Hytrin or Cardura caused IFIS.â€
The studies say their review of the pharmacologic literature suggests that the same alpha-1A receptor subtype is also present in the iris dilator smooth muscle. â€œWe postulate that prolonged pharmacologic blockade results in loss of normal iris dilator smooth muscle tone. This deficient tone produces the floppy iris behavior caused by normal intraocular fluid currents during surgery,â€ wrote the authors.
The authors described the clinical features of IFIS, based upon more than 30 cases that are reported in their paper. In addition to subnormal preoperative pupil dilation, IFIS is characterized by repeated incisional prolapse of a billowing, floppy iris, causing progressive intraoperative miosis that is not prevented by sphincterotomies and mechanical pupil stretching. Their retrospective study documented a higher rate of posterior capsule rupture.
In the article, the authors recommend that preoperative male patients should be questioned about Flomax ® use, particularly if the pupil dilates poorly. They found that temporarily stopping the medication for two weeks often improved, but did not eliminate the floppy behavior of the iris, and that in a few cases, IFIS still occurred in patients that were off Flomax ® for one year.
The authors also provide recommendations for maintaining the dilation and stability of the iris during cataract surgery. â€œWe strongly recommend the use of iris hooks, or an iris expansion ring to maintain an adequate surgical pupil diameterâ€ They go on to say that because these devices are difficult to insert without ensnaring the capsulorhexis, â€œanticipation of IFIS allows surgeons to reconsider their usual method of small pupil management in favor of self-retaining pupil expansion devices inserted prior to capsulorhexis initiationâ€.
â€œIn conclusion, IFIS is a newly described small pupil syndrome that appears to be associated with the use of a medication that is commonly used in the elderly male population. Because of the higher risk of posterior capsule rupture and iris trauma associated with IFIS cases, we believe that recognizing and anticipating these cases will be important in enabling surgeons to reduce the complication rate,â€ the author wrote.
â€œI wish to emphasize that there has been no indication that Flomax causes any symptoms or problems in unoperated eyes, and we are not recommending that Flomax prescribing practices be changed,â€™ said the author. â€œRather, we want to educate ophthalmologists about this syndrome, so that upon eliciting any history of Flomax use, they can anticipate IFIS and follow the surgical recommendations from our study,â€ the author added.
We urge physicians to report their experiences with Flomax® patients and their methods for dealing with intraoperative complications. Doing so will enable us to make recommendations regarding Flomax and similar medications.