Incidence of TASS on decline

Take-home

A recent analysis has found that the incidence of toxic anterior segment syndrome has declined. Improvements in materials and methods may be the reason.

Dr. Mamalis

By Liz Meszaros; Reviewed by Nick Mamalis, MD

Salt Lake City-The incidence of toxic anterior segment syndrome (TASS) is on the decline, according to recent analysis of survey data collected from 2007 to the present, said Nick Mamalis, MD.

He presented data from a recent analysis he conducted with fellow researchers.

TASS is an acute postoperative inflammation of the anterior segment. TASS is sterile and non-infectious, and in almost all cases, occurs after an uneventful cataract surgery or more recently, after phakic IOL implantation, and usually of immediate onset (12 to 48 hours postoperatively or sooner).

Clinical findings of TASS include diffuse “limbus-to-limbus” corneal edema” and widespread endothelial damage, explained Dr. Mamalis, director of the Ophthalmic Pathology Laboratory, University of Utah Health Care, Salt Lake City, and director of the Intermountain Ocular Research Center.

In addition, patients with TASS will also have marked anterior segment inflammation, fibrin, and hypopyon.

To ascertain the incidence of TASS, researchers analyzed data culled from submitted questionnaires. From 2007 to the present, the task force received responses from surgical sites that were self-reporting cases of TASS. In 2010, Cutler-Peck et al. published a retrospective analysis of the first half of the survey data.

Dr. Mamalis and colleagues presented an updated analysis of the survey data collected to date, and included information collected by the ASCRS TASS Task Force during site visits.

Materials and methods

Surveys were collected between June 1, 2007, and March 1, 2012. Questions were designed to elicit information about cleaning and instrument processing, and medications and products used in the perioperative period.

A retrospective analysis was done on data collected. Results from June 2, 2009 to March 1, 2012 (Group B) were compared with earlier results from January 1, 2007, through May 31, 2009 (Group A) to identify trends.

A total of 130 questionnaires were submitted and included in the analysis, along with data from 71 site visits. There were a total of 1,570 cases of TASS of the approximately 69,000 cataract surgeries performed at reporting centers.

Upon analysis, data showed that instrument processing was the factor most commonly associated with TASS. This included inadequate flushing of phaco and I/A hand-pieces, use of enzymatic cleaners, detergents, poor instrument maintenance and processing, and reuse of single-use products.

Product questionnaires were directed at finding the incidence of products associated with TASS. These included the use of antibiotics in balanced salt solution, preserved epinephrine, inappropriate agents for skin preparation, and powdered gloves.

Importantly, Dr. Mamalis and colleagues found that the number of outbreaks reported is trending downward, and there was no spike in outbreaks seen in association with the discontinuation of several brands of preservative- and stabilizer-free epinephrine.

“In conclusion, the frequency of TASS outbreaks has declined and encouraging trends in the adequate cleaning and processing of ophthalmic instruments were noted,” Dr. Mamalis said. “However, the increased use of enzymatic detergents and ultrasound baths were an unfavorable trend. Increased awareness of TASS and its most common risk factors may reduce the risk of TASS.”

Suggested reading

Bodnar Z, Clouser S, Mamalis N. Toxic anterior segment syndrome. Update on the most common causes. J Cataract Refract Surg. 2012;38:1902-1910. doi: 10.1016/j.jcrs.2012.06.053. Epub 2012 Sep 19.

Nick Mamalis, MD

P: 801/581-6586

E: nick.mamalis@hsc.utah.edu

Dr. Mamalis is a consultant/advisor for Abbott Medical Optics, Anew Optics, Medennium, and OptiMedica. He also performs contract research studies for Abbott Medical Optics, Alcon Laboratories, Allergan, Anew Optics, Bausch + Lomb, Calhoun Vision Inc., MBI, and Power Vision Inc.

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TASS: What's trending

Positive trends were seen in recent data regarding the incidence of toxic anterior segment syndrome, noted Nick Mamalis, MD, and included:

More sites reported adequate hand-piece flushing volumes. In Group B, hand-piece flushing volume of 120 ml or more was reported by 66% of respondents, as compared with only 48% of those in Group A. In addition, the number of respondents using less than 120 ml was greater in the Group A than in Group B (39% versus 26%, respectively).

Fewer sites used reusable cannulas. In Group A, 86% of respondents used reusable cannulas, compared with only 77% in Group B.

The use of distilled/deionized final rinse solutions was increased. In Group A, 46% of respondents reported using deinonized/distilled rinse water, compared with 68% in Group B. In addition, a full 32% of the respondents in Group A reported using sterile/pyrogen-free rinse water, compared with only 13% in Group B. The use of tap water in these groups was 19% versus 11%, respectively.

Antiobiotics were added to balanced salt solution less frequently. This difference, however, was not great; with 80% of respondents from Group B adding no antibiotics, compared with 76% of those in Group A. Similar as well were the rates of those who added vancomycin (15% versus 20%, respectively) and gentamycin (5% versus 3%).

Finally, the use of preserved intracameral anesthetics was decreased. In Group A, 77% of respondents reported not using these solutions, compared with 84% in Group B. One negative trend, noted Dr. Mamalis, was the increased use of enzymatic detergents and ultrasonic baths, which was seen to be increased in Group B compared with Group A (71% versus 62%, respectively). In addition, the use of enzymatic detergents increased, with 49% of Group A reporting used, compared with 58% of Group B.