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Solving the ‘-osin’ mystery
Thorough preoperative planning is key in avoiding potential IFIS-related complications during and after cataract surgery.
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Intraoperative floppy iris syndrome, or IFIS, was first described by Chang and Campbell in 2005 as an excessive billowing or floppiness of the mid-peripheral iris during routine cataract surgery. This excessive floppiness historically wreaked havoc even for the experienced phaco surgeon, causing iris prolapse through the main and/or side-port incisions, as well as the possibility for intraoperative progressive miosis and poor proper preoperative pupil dilation.
In a 2008 survey among cataract surgeons in the American Society of Cataract and Refractive Surgery, an overall complication rate of 77% was reported, with 23% of cases involving posterior capsule rupture/vitreous loss and 52% involving iris trauma to some degree.
Of those surveyed, 59% recommended an eye exam prior to initiating Flomax (tamsulosin, Boehringer Ingelheim) or a similar therapy, such as the Plaquenil (hydroxychloroquine, Sanofi Aventis) approach taken today. What was more surprising was that 49% of the surveyed ophthalmologists said they would have their own cataract removed at an even earlier stage, prior to initiating tamsulosin therapy.
The ‘-osin’ class
IFIS is not restricted to tamsulosin use alone but instead can result from systemic use of any of the alpha-1 adrenergic antagonists used to treat benign prostatic hypertrophy, whose generic names all end with the suffix “-osin.” This class of drugs includes Rapaflo (silodosin, Watson Pharma), as well as nonspecific alpha-1 antagonists such as Hytrin (terazosin, Abbott Laboratories), Cardura (doxazosin mesylate, Pfizer) and Uroxatral (alfuzosin, Sanofi Aventis).
The common thread among these medications is that they all affect the alpha-1a receptor subtype predominant in the prostate muscle the same way they affect the iris dilator muscle. Chang has reported that stopping these medications preoperatively is unpredictable, as they can still cause IFIS even years after stopping their use. Therefore, in my practice’s preoperative questionnaire, we ask whether the patient is or has ever been on tamsulosin or a similar medicine ending in -osin, even if it was just one pill one time.
Treatment options
There are many treatment options suggested, reported and published in the literature for IFIS. Atropine drops three times per day for 1 to 2 days preoperatively is one option; however, this has the potential to cause acute urinary retention, so patients are advised not to stop their -osin medication. The popular “Shugarcaine” approach, which combines intracameral phenylephrine, epinephrine and lidocaine in a preservative-free dilution solution, is an effective alternative.
A simple change in operative technique to bimanual microincisional cataract surgery allows for irrigation to remain anterior to the iris, lessening IFIS due to tighter incisions and a more stable anterior chamber. Osher and Koch have utilized their “donut technique,” whereby placing a maximally dispersive ophthalmic viscosurgical device, such as Healon 5 (Abbott Medical Optics), peripherally and a maximally cohesive ophthalmic viscosurgical device centrally, such as Viscoat (4% chondroitin sulfate, 3% sodium hyaluronate, Alcon) or EndoCoat (sodium hyaluronate 3%, Abbott Laboratories), keeps the iris stable.
Pupillary expansion devices
More recently, pupillary expansion devices have become surgeons’ first choice to conquer IFIS; however, devices such as the Graether 2000 Pupil Expander (Eagle Vision), the Perfect Pupil Injector PPI (Milvella), and the Morcher 5S pupil ring (FCI Ophthalmics) can all be bulky and difficult to position in pupils of less than 4 mm or in shallow anterior chambers.
The Malyugin ring (MicroSurgical Technology) allows for easy placement into the eye but still poses challenges with possible iris damage upon removal; interference with instrumentation, especially at the main incision site; and, on average, maximal pupil dilation to only 6 mm.
The newest pupil expansion device from APX Ophthalmology avoids many of the drawbacks found with the Malyugin ring, allowing for easier insertion and removal, as well as pupil dilation up to 8 mm.
Lastly, iris hooks in square or diamond configurations, depending on surgeon preference, offer a viable option with easy insertion and removal capability. In cases in which -osin use was missed preoperatively and suddenly presents itself as IFIS intraoperatively, my preference is to use a subincisional single iris hook. I will add an additional stab incision below the main incision to allow placement of an iris hook. This single iris hook technique described by Tint et al allows for an easy resolution for unplanned IFIS cases.
In the end, IFIS no longer has to be the bad guy during cataract surgery. Knowing that IFIS can have serious visual consequences, proper preoperative planning with intracameral dilating solutions, pupillary expansion devices, and/or iris hooks can be sight-saving in cases in which the patient is or has used an -osin drug. Solving challenges is what we do best as ophthalmologists, and that includes solving the -osin mystery.
I hope you will join me for the next installment of my column, “How to achieve a pristine ocular surface.”
References:
Bendel RE, et al. J Catract Refract Surg. 2006;doi:10.1016/j.jcrs.2006.04.039.Chang DF, et al. J Cataract Refract Surg. 2005;doi:10.1016/j.jcrs.2005.02.027.
Chang DF, et al. J Cataract Refract Surg. 2008;doi:10.1016/j.jcrs.2008.04.014
Chang DF, et al. J Cataract Refract Surg. 2005;31(4):664-673.
Gurbaxani A, et al. Eye (Lond). 2007;doi:10.1038/sj.eye.6702172.
Oetting TA, et al. J Cataract Refract Surg. 2002;doi:10.1016/S0886-3350(01)01100-2.
Shugar JK. J Cataract Refract Surg. 2006;doi:10.1016/j.jcrs.2006.01.110.
Tint NL, et al. J Cataract Refract Surg. 2009;doi:10.1016/j.jcrs.2009.06.020.
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Disclosure: Jackson has no relevant financial disclosures.