ASCRS Urgent Communication-TASS

April 2006

M E M O R A N D U M
To: ASCRS Members
URGENT COMMUNICATION

Toxic Anterior Segment Syndrome (TASS) Alert

This alert is brought to you as a member service through the collaborative activity of the American Society of Cataract and Refractive Surgery (ASCRS) and the American Academy of Ophthalmology (AAO).

Over the past several weeks, numerous eye centers throughout North America have been reporting an increased incidence in the occurrence of toxic anterior segment syndrome (TASS) following outpatient cataract surgery. The recent increase in the number of reported TASS cases is very similar to the outbreak that occurred in the late fall of 2005, which was found to be related to endotoxin contamination of BSS manufactured by Cytosol Ophthalmics. Following recall of the Cytosol products, including AMO Endosol, this outbreak seemed to have subsided by the beginning of 2006. However, a new outbreak of TASS appears to have started in approximately March of 2006, is ongoing, and is unrelated to the Endosol product.

TASS is an acute, sterile anterior segment inflammation following generally uneventful cataract and anterior segment surgery. One of the main factors in differentiating TASS from an infectious endophthalmitis is the rapid onset. Most patients with TASS will develop symptoms within 12 to 24 hours of the surgery. Common findings on anterior segment slit lamp examination include increased cell and flare with associated fibrin and possible hypopyon formation. Patients may show signs of diffuse corneal edema, and they may also show signs of iris atrophy with pupillary abnormalities and eventual increased intraocular pressure. It is important to differentiate sterile postoperative inflammation from infectious endophthalmitis as the evaluation and treatment of these patients are markedly different. Patients with TASS will often respond quite rapidly to treatment with intense topical corticosteroids. It is important that the patients be evaluated often to ensure that the inflammation is clearing and that the patient’s intraocular pressure is under control. The clearing of the inflammation and eventual patient outcome is related to the severity of the toxic insult at the time of surgery. Fortunately, most patients reported to date are in the category of a moderate toxic inflammation.

The etiology of the present outbreak is unclear. TASS may be related to problems with any irrigating solution or other solution placed in the patient’s eye during surgery including BSS or anything added to the BSS. Material placed in the eye during surgery such as anesthetics, OVDs, antibiotics, or other medications has been found to be related to TASS. Problems related to the cleaning and sterilization of instruments for cataract surgery have been found to be a common source of TASS.

Aided by a grant from the ASCRS, Nick Mamalis, MD, professor of ophthalmology at the University of Utah has analyzed outbreaks of TASS as well as postoperative endophthalmitis for the past 15 years at the John A. Moran Eye Center. He reports a marked increase in the incidence of TASS cases reported in recent weeks. Dr. Mamalis’ lab at the John A. Moran Eye Center is working closely with Dr. Henry Edelhauser from Emory University as well as the Centers for Disease Control in Atlanta. (A review of TASS symptoms and treatment by Drs. Mamalis and Edelhauser appears in the February issue of the Journal of Cataract & Refractive Surgery.) Company representatives have also been involved in the analysis of these early reported cases. Detailed analysis of the cases reported to date is ongoing and as potential etiologic factors are further evaluated, it is hoped that the source of this outbreak can be elucidated in a rapid manner.

In the meantime, anterior segment surgeons should be aware of this ongoing outbreak of TASS and should have a high index of suspicion regarding increased postoperative inflammation following cataract and anterior segment surgery. Suspicious outbreaks should be reported to Dr. Mamalis at the Intermountain Ocular Research Center at the University of Utah. E-mail: nick.mamalis@hsc.utah.edu, phone: 801-581-6586, fax: 801- 581- 3357. Alternatively, contact the Center for Disease Control at: CDC Division of Health Care Quality Promotion,
1-800-893-0485.