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TASS rate ‘appears to be growing,’ surgeon warns
Doctors urged to be alert for changes in protocol to avoid cases of toxic anterior segment syndrome.
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KOLOA, Hawaii — The incidence of toxic anterior segment syndrome is low — estimated at 0.1% to 2% — but “it appears to be growing,” according to one surgeon speaking here.
In light of this, Terry Kim, MD, said the surgeon is the key to recognizing the problem immediately and alerting the appropriate staff or other centers to take swift action. Toxic anterior segment syndrome (TASS) occurs in clusters or outbreaks, so it could affect a large number of patients in a short amount of time.
“Your hospital or ASC may have changed some aspect of the sterilization protocol without your knowledge,” Dr. Kim said at Saturday Subspecialty Day, preceding the Hawaiian Eye 2007 meeting. “It is certainly an environmental and toxic-control issue, and it does require an investigation and a complete analysis to determine the cause.”
Dr. Kim urged surgeons to pay close attention to any medication they inject into the anterior chamber and to be attuned to any changes in operating room and sterilization protocols.
“You are the key in identifying any epidemic of TASS because you’re the only person from the operating room that will be seeing these patients postoperatively,” he told the audience.
Surgeons should take prophylactic measures to ensure that TASS and other infections do not enter the eye perio- or postoperatively, Dr. Kim said.
Intraocular medications
For supplemental intracameral anesthesia, Dr. Kim recommended using a sterile solution of lidocaine HCl that is preservative-free, meaning that it does not contain methylparaben.
 Terry Kim |
“That is extremely important. You do not want to use anything that contains a methylparaben preservative, otherwise you will experience significant endothelial toxicity that will result in TASS,” he said.
Dr. Kim also advised refraining from the use of higher lidocaine concentrations, as well as related compounds such as bupicacaine or tetracaine. A single or multi-dose container of lidocaine is safe to use “because it does get washed out during your phacoemulsification procedure,” he said.
Some surgeons are also using intracameral epinephrine to help dilate the pupil during cataract surgery, he said. “You should use preservative-free epinephrine,” Dr. Kim said. “You want to make sure you dilute the epinephrine to have a final concentration of 1:100,000.”
When using intraoperative miotic agents, surgeons have a choice between Miochol-E (acetylcholine chloride, Novartis Ophthalmics) and Miostat (carbachol, Alcon), but he urged surgeons to make sure the components are thoroughly mixed.
Since first reported by Burke and colleagues, surgeons have also increased the use of intracameral triamcinolone to stain and better visualize vitreous encountered during cataract surgery. Dr. Kim described a protocol for “washing out the preservative” in the Kenalog (triamcinolone acetonide, Bristol-Myers Squibb) suspension to end up with a 1:10 dilution of the triamcinolone.
Finally, the results from the European Society of Cataract and Refractive Surgeons’ Endophthalmitis Study Group, which revealed lower endophthalmitis rates in patients treated with intracameral cefuroxime, may affect current trends in antibiotic prophylaxis. Dr. Kim stated, “It will be interesting to see if U.S. surgeons start adopting this technique and if we start seeing more TASS due to dilutional errors during formulation.”
Causes of TASS
There are a variety of reasons why TASS is on the rise, Dr. Kim said.
Irrigating solutions, ophthalmic viscoelastic devices, ophthalmic instrument contaminants, IOLs and ocular medications are some of the things that may be to blame, he said.
With the increasing use of intracameral medications, Dr. Kim said there will probably be a consequential increase in the number of TASS cases, whether it is from incorrect solution concentrations, pH, osmolality, preservatives or toxins.
Clinical course and treatment
Taking action to prevent TASS is the real goal, Dr. Kim said.
“Once you have introduced [TASS] into the anterior chamber, it has already done the damage,” he said.
The mainstay of treatment, however, is intense topical corticosteroids, Dr. Kim said. He typically treats with prednisolone acetate 1% every hour and oral prednisone, if necessary.
“These patients are also prone to glaucoma and cystoid macular edema from the severity of the anterior chamber inflammation, so you really have to follow these patients carefully,” he said.
TASS is an environmental and toxic-control issue, Dr. Kim said.
“It does require investigation and complete analysis, so you should really pay attention to any medication you are injecting into the anterior chamber and any fluids that you are irrigating into the anterior chamber, being aware of any changes in operating room and sterilization protocols,” he said.
Dr. Kim said any suspected TASS cases should be reported to Nick Mamalis, MD, or Henry F. Edelhauser, PhD, who each head centers designated for investigating cases of TASS (see box, below).
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For more information:
- Terry Kim, MD, can be reached at Duke Eye Center, 2351 Erwin Road, P.O. Box 3802, Durham, NC 27710-3802; 919-681-3568; fax: 919-681-7661; e-mail: terry.kim@duke.edu. Dr. Kim receives grant support from Alcon Laboratories and Allergan and serves as a consultant for Hyperbranch Medical Technologies Inc. and Becton-Dickinson Ophthalmics. He is a member of the speakers’ bureaus for Alcon, Allergan, Bausch & Lomb and Ista Pharmaceuticals.
References:
- Barry P, Seal DV, et al. ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery: Preliminary report of principal results from a European multicenter study. J Cataract Refract Surg. 2006;32:407-410. Erratum in: J Cataract Refract Surg. 2006;32:709.
- Burk SE, Da Mata AP, et al. Visualizing vitreous using Kenalog suspension. J Cataract Refract Surg. 2003;29:645-651.
- Mamalis N, Edelhauser HF, et al. Toxic anterior segment syndrome. J Cataract Refract Surg. 2006;32:324-333.
- Daniele Cruz is an OSN Staff Writer who covers all aspects of ophthalmology, focusing on optics, refraction and contact lenses.
- Lauren Wolkoff is Executive Editor of OSN U.S. Edition.