EyeWorld Asia-Pacific March 2020 Issue

EWAP MARCH 2020 25 SECONDARY FEATURE C ataract surgeons are seeing more patients who have used—or are using— tamsulosin.  “Tamsulosin [Flomax, Astellas Pharma] is one of the most frequently used urologic agents in males for reduced urinary flow,” William Myers, MD, told EyeWorld via email. “As many patients undergoing cataract surgery have concomitant prostatic hypertrophy, many are already on or have tried tamsulosin. At the VA, nearly 75% patients are not naïve with respect to alpha blockers.” “A significant percentage of patients are taking these medications, most commonly for benign prostate hyperplasia,” Bryan Lee, MD, JD, agreed. “However, they are used for other reasons, such as making it easier to remove a Foley catheter or to help pass a kidney stone. They are also being used more commonly in women, so it is important to ask for a history of use and to cover not only tamsulosin but also the other medications with the same mechanism of action.” EyeWorld corresponded with Drs. Lee, Myers, and Steven Safran, MD, PA, to discuss the effects of alpha-1 adrenergic antagonists (or blockers) on the eye and find out what ophthalmologists need to know about their use. Iris changes Intraoperative floppy iris syndrome (IFIS) is the main concern when it comes to patients with a history of alpha-1 blocker use. “IFIS was first reported as an association by Campbell and Chang in 2005 1 ,” wrote Dr. Myers. “This creates increased risk of iris instability and pupil constriction during cataract surgery, increasing the risk of complications. Most patients are male, but tamsulosin is also used in female patients with urinary flow issues.” In his experience, alpha-1 blockers can affect the iris after just one dose. “I cared for a patient with IFIS who had to stop tamsulosin after a single dose as he had a neuroleptic seizure develop,” he noted. Dr. Safran offered a different experience. “Some patients are on these meds for years with little effect and others within a few months can see an effect,” he wrote. However, he emphasized that “[t]he effect once it kicks in is permanent, because there are histologic changes to the iris with atrophy of the dilator muscles.” These changes were detailed by Ricardo Santaella, MD, and colleagues in a paper published in Ophthalmology in 2010. 2 The retrospective, case-control study involved 51 cadaveric eyes from 27 patients—14 of whom used tamsulosin, leaving 13 in the control group. Dr. Santaella and his colleagues reviewed patient histories, recorded duration and dosage of tamsulosin use, and conducted light microscopic review and morphometric analysis of the eyes, measuring the maximum and minimum iris dilator muscle thickness and iris stromal thickness. The group found that the “mean iris dilator muscle thickness in the tamsulosin- treated group (6.53±1.99 µm) was significantly thinner compared with that of the control group (8.50±1.61 µm) (p=0.006),” though no direct relationship was found between the iris changes and the dose and duration of tamsulosin use. Because the effect is irreversible, the doctors agreed that there is no point asking the patient to stop using the blocker prior to surgery. “I never ask patients to stop, I just want to make sure that I know about a history of current or prior use,” Dr. Lee wrote. “The only reason to stop the medication is if they just started it,” Dr. Safran wrote. “If they have been on it for a while and the effect is already in place on the iris, then stopping it will make no difference.” Medical intervention So what can be done to reduce a floppy iris? “There are a few different approaches to try to reduce it medically,” Dr. Lee wrote. “I Alpha-1 blockers, the iris, and ophthalmic surgery by Chiles Samaniego EyeWorld Asia-Pacific Senior Staff Writer AT A GLANCE • While most frequently used in men to manage prostatic hypertrophy, alpha-1 adrenergic blockers are also used to ease the removal of a catheter and help pass a kidney stone. They are now more commonly being used by women. • Alpha-1 blockers effect irreversible histologic changes in the iris, with no direct relationship to dose or duration of use. • Pharmacological management with epinephrine and phenylephrine can be enough to manage a floppy iris but iris hooks and rings can also be useful. • Ophthalmologists should be aware of other possible causes of IFIS, including diabetes and some viral infections. This article originally appeared in the January-February 2020 issue of EyeWorld . It has been slightly modified and appears here with permission from the ASCRS Ophthalmic Services Corp. Contact information Lee: bryanlee@post.harvard.edu Myers: wmyers2020@gmail.com Safran: safran12@comcast.net This is a patient on tamsulosin referred after complicated cataract surgery due to IFIS. There is iris damage and anterior and posterior capsule damage with dislo- cation of the IOL.