Alpha blockers can complicate surgery
DEAR DOCTOR: I am a 76-year-old man, very active and in fairly good health. I need cataract surgery, but I have learned that serious complications can occur with patients who are on Flomax, as I recently was. Can you explain?
DEAR READER: You’re referring to a possible complication during cataract surgery known as “intraoperative floppy iris syndrome,” or IFIS. As you mention in your letter, it can occur in patients who take — or have taken — Flomax, which is the brand name for the drug tamsulosin. It’s one of a class of drugs known as alpha blockers, which relax smooth muscle in the body — the type of muscle that controls the bladder, the urinary tract, blood vessels and the intestines. Flomax helps to relax smooth muscle by interfering with the action of the hormone norepinephrine. Some medications in this class of drugs can be part of a treatment plan to address high blood pressure. Other types of alpha blockers, such as Flomax, are used to improve the flow of urine in older men with an enlarged prostate.
It turns out that alpha blockers can also affect the muscles of the eye. During cataract surgery, a procedure to restore clear vision when the lens has grown cloudy, the surgeon needs to dilate, or widen, the iris. The iris is the ring-shaped membrane in front of the lens. It gives our eyes their color, and the adjustable center of the iris forms the pupil. Flomax can cause a loss of muscle tone in the iris — that’s the “floppy iris” in the name of the condition — which affects how effectively the pupil can dilate. Poor dilation can impede the successful removal of the cataract. It can also lead to additional and serious complications that can threaten vision.
Stopping Flomax use prior to surgery may not help. The drug doesn’t cause anatomical changes to the eye, but its relaxing effect on eye muscles can last years. Other drugs used to improve urine flow due to enlarged prostate have also been associated with IFIS, but to differing degrees.
The good news is there are several ways to reduce risk and improve outcomes during surgery. This includes the off-label use of ephedrine, a hormone and neurotransmitter, which has been shown to improve muscle tone in the muscle that controls dilation of the iris. According to the American Academy of Ophthalmology, ephedrine has been used in cataract surgery with very good results. Surgeons can adjust surgical techniques, use a blue stain to better view certain areas of the eye and adjust the force of irrigation during surgery. There is also evidence that patients whose eyes don’t dilate well during the initial eye exam may be at increased risk of developing IFIS during cataract surgery.
Let your ophthalmologist know of your history with alpha blockers. Look for a doctor who has experience with your particular situation.