Cases of toxic anterior segment syndrome (TASS) have been reported in the literature for nearly two decades. However, the condition has remained a relatively underrecognized potential complication associated with cataract surgery. “Until recently, individual outbreaks occurred sporadically, but no major epidemics had been identified. For the most part, ophthalmologists and surgical centers were simply unaware that it was occurring,” said Nick Mamalis, MD, professor of ophthalmology and director of the ophthalmic pathology laboratory at the University of Utah, Salt Lake City. But that all changed in the spring of 2006 when there was a sharp rise in the number of ophthalmologists and surgical centers seeking the assistance of Dr. Mamalis and Henry F. Edelhauser, PhD, professor of ophthalmology and director of ophthalmic research at Emory University, who had also been investigating cases of TASS.
Tagging it TASS. TASS is often misdiagnosed and frequently mistaken for infectious endophthalmitis. In contrast to infectious endophthalmitis, however, the postoperative inflammation related to TASS generally occurs within 12 to 24 hours after cataract surgery, differs in presentation, and is thought to be a result of external factors—specifically, tainted solutions or contaminated surgical equipment related to the implantation of intraocular lenses.
Because the potential culprits are myriad, finding the precise etiology of a TASS outbreak can be a challenge. In response to the 2006 spike in reported cases, Drs. Mamalis and Edelhauser created an ad hoc investigative task force with the support of the American Society for Cataract and Refractive Surgery (ASCRS) and funding from the ASCRS Foundation. They did this in collaboration with the Academy, the FDA, Walter Hellinger, MD, an epidemiologist from the Mayo Clinic, and other representatives of the ophthalmic community.
Under One Roof
Acting as a clearinghouse for information, the ASCRS TASS Task Force created two standardized questionnaires.1 These were designed to obtain information about the products and instruments used during cataract surgery and to build a database for the vast amount of information being collected. They can be downloaded at www.ascrs.org/TASS/Instrument-Re-processing-Product-Questionnaire-Survey.cfm.
TASS no longer a problem? By June 2006, the outbreak quieted as quickly as it had erupted. “We have found that the rate of these inflammations has dropped to what we consider a baseline level. We still get occasional inquiries. But instead of having several hundred cases reported over a short period of time, we are back to only encountering periodic cases,” said Dr. Mamalis.
Calling All Culprits
The task force published preliminary2
and then final reports3
that described their findings. Although the team found different causes for the outbreaks from center to center and no underlying common source, one of the most important pieces of information that was gleaned from the data was that “the routine cleaning and sterilization of ophthalmic equipment varied greatly from center to center, and there were no uniform guidelines being followed in many of the centers. Or there were guidelines in place, but the staff simply was not following them for a variety of reasons,” said Dr. Mamalis. Hence, some cases of TASS were traced back to insufficient or improper sterilization practices. Based on these findings, the task force, in conjunction with the FDA, the CDC and the American Society of Ophthalmic Registered Nurses outlined their recommended practices for the cleaning and sterilization of surgical equipment in a special report published in the Journal of Cataract and Refractive Surgery.4
The task force will remain in place to react to future outbreaks, but with the current diminution of TASS occurrences, the task force now focuses on educating surgeons and others at surgical centers about TASS and providing them with its best recommendations for prevention, said Dr. Mamalis.
FDA investigation. During the outbreak, the FDA also received multiple reports of suspected cases of TASS. While some of the cases may have coincided with those reported to the TASS Task Force, the FDA began its own investigation. It examined the ophthalmic medical products implicated in several TASS outbreaks. In the past, the FDA took regulatory action based on their findings—overseeing, for example, withdrawal of Cytosol BSS.
Another candidate culprit. Like the TASS Task Force, the FDA garnered some important information from its investigations. “Several problematic areas were identified that have hampered the expeditious investigation of TASS outbreaks. Specifically, there is a lack of product traceability and an underreporting of cases. We also found poor communication among the stakeholders and a lack of established methodology for testing the suspected samples. These are all issues that must be addressed in order to effectively combat TASS,” said Malvina Eydelman, MD, director of the division of ophthalmic and ENT devices (DOED) at the Center for Devices and Radiological Health (CDRH) of the FDA.
Designed to utilize the expertise of the various offices within CDRH and the FDA, the Proactive TASS Program (PTP) was created to address the identified problems. “While the PTP was generated as a response to recurring TASS outbreaks, it is one of the first programs that takes a proactive stance to prepare us for potential future outbreaks,” said Kesia Alexander, PhD, chief of the intraocular and corneal implants branch of the DOED and one of the principal coordinators of the program.
A Joint Academy/ASCRS TASS Communication Task Force was formed in 2007 to assist the PTP in communicating information to the ophthalmic community about the program and the critical measures that must be taken by everyone in order to curtail the impact of TASS. “PTP’s success in minimizing future TASS outbreaks is highly dependent on participation by all ophthalmologists in the United States,” said Dr. Eydelman.
|To Report a Suspect |
When a report is filed with the FDA about a case of TASS, privacy is guaranteed. Under the Freedom of Information Act, the FDA will not disclose the reporter’s identity in response to a request from the public. The reporter’s identity, including the identity of a self-reporter, may be shared with the manufacturer unless requested otherwise by checking a box on the form.
To ensure that the necessary information related to TASS cases associated with ophthalmic products are appropriately captured, reporters are encouraged to submit information on a MedWatch reporting form, which can be found at www.fda.gov/medwatch/report.htm.
Prompt and Accurate Reporting
“While we think that the cleaning and sterilization recommendations are certainly going to help control TASS incidences, we feel our proactive program should limit any epidemic that may be specific to a particular medical product,” explained Dr. Eydelman. To achieve this goal, she said, “Voluntary reporting to the FDA of device-related problems is a critical professional and public health responsibility.”
The success of these programs, and therefore the control of TASS, are dependent on surgeons and surgical centers keeping detailed records of all products and equipment used during cataract surgery; product traceability is essential. “One of the key points we want to communicate to the ophthalmic community is the need for product traceability. We must capture a lot more information than is the current standard of care,” said Dr. Eydelman.
Only you can prevent TASS. Voluntary reporting takes place under MedWatch,5 a program that allows health care professionals and consumers to report serious problems that they suspect are associated with the medical devices they prescribe, dispense or use.
When MedWatch forms are received, “they will be tracked and reviewed on a routine basis by our staff. We will have an inherent program built in, which will continuously scan the background occurrence of TASS,” said Dr. Eydelman.
Using the information reported to the FDA, in cases where a TASS outbreak may be device-related, the PTP program will test those devices to determine whether they are causing the TASS. All of this, said Dr. Eydelman, “allows us to be on the leading edge rather than on the responsive end of an epidemic.”
4 Mamalis, N. et al. J Cataract Refract Surg
2007;33(6):1095–1100. Also available free of charge at www.ascrs.org/TASS/upload/TASS_guidelines.pdf
The experts interviewed for this story report no related financial interests. Special thanks to Don Calogero, senior biomedical engineer in the FDA’s division of ophthalmic and ENT devices, for his assistance with this article.