EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/618732
EW NEWS & OPINION 8 December 2015 The purpose of enzymatic deter- gent is to remove bulk biomaterial from surgical instruments. However, intraocular instruments acquire minimal bioburden during surgery and the material they do collect is usually completely removed with prompt manual rinsing and clean- ing. Even minute enzyme residue left on intraocular instruments can cause TASS, and the small diameter lumens and fragile nature of intra- ocular instruments makes complete removal of all traces of detergent difficult. Therefore, enzymatic deter- gents may elevate the risk for TASS without providing any significant benefit to the patient. Recent publications reported that the most commonly identified risk factors for TASS are related to improper instrument cleaning. The ASCRS TASS Task Force analyzed and compared causes of TASS during two periods: 2007–2009 and 2009– 2012. 4,5 Data from 130 question- naires and 71 site visits to affected ASCs was incorporated into the final analysis of 1,454 cases of TASS from approximately 69,000 concomitant cataract surgeries. The most com- mon risk factors for TASS included inadequate flushing of handpieces, use of enzyme detergents, and use of ultrasound baths. 5 Based on the pub- lished ASCRS TASS Task Force find- ings, we conclude that if intraocular surgical instruments are thoroughly rinsed with sterile distilled or deion- ized water promptly after each use, then the use of enzyme detergents is unnecessary. If enzyme detergents are used, instructions for proper dilution and disposal of cleaning solutions should be followed. The instruments should be thoroughly rinsed to ensure removal of all detergent. Because tap water may contain heat-stable endotoxin from gram negative bac- teria found in the municipal water supply, sterile distilled or sterile deionized water should be used for the final instrument rinse. Avoiding enzyme detergent for intraocular instruments is a com- mon practice among ASCs. In 2014, a survey developed by ASCRS, AAO, and OOSS was sent to OOSS member ophthalmic single specialty ASCs re- garding cleaning and sterilization of intraocular instruments. Complete responses were received from 182 ASCs. A majority (55.5%) did not use enzyme for intraocular instru- ment decontamination, compared with 44.5% who did. The average self-reported rate of endophthalmitis was 0.021% for non-enzyme-using ASCRS continued from page 3 will frequently tap and treat with intravitreal antibiotics, even if they think the chance of infection is low, because of the risk of being wrong," he said. "Meanwhile, besides TASS complications, the patient will be subjected to the emotional trauma of believing that they have a poten- tially blinding infection." By issuing this clinical guide- line, Dr. Chang said ASCRS is committed to educating ophthal- mologists and their ASC staff on the potential risk of using enzymatic cleaners with an "unproven en- dophthalmitis benefit" and defend- ing ASCs "who choose not to use enzymes routinely because of these TASS risks. We have sent these clini- cal guidelines to CMS with the hope of better educating their surveyors about the unintended risk to pa- tients posed by requiring enzymatic detergent," he said. The following is the text of the guidelines issued by the 3 societies. Recommendations regarding use of enzyme detergent for cleaning intraocular surgical instruments Toxic anterior segment syndrome (TASS) and postoperative infectious endophthalmitis are rare but poten- tially sight threatening complica- tions of cataract and other intraoc- ular surgeries. Particularly because of the high frequency of cataract surgery, improper instrument clean- ing practices pose a significant risk to patients. Because of conflicting guidelines, one practice that is con- troversial and of concern to regula- tory agencies is the use of enzymatic detergents for decontaminating intraocular surgical instruments. The manufacturer's instructions for use (IFU) that accompanies oph- thalmic instruments and ultrasound cleaning baths often calls for the use of enzymatic cleaners. However, the necessity of enzymatic detergents for cleaning contaminated intraocular instruments has not been estab- lished. Contrary to some manu- facturers' IFUs, it is our position that enzymatic detergents should not be required for intraocular instruments for several reasons. These detergents typically contain exotoxins subtilisin or alpha amy- lase, neither of which are denatured by autoclave sterilization. Corneal endothelial toxicity from enzymatic detergents has been documented in both animal and human studies. 1,2 Inappropriate use or incomplete rinsing of enzymatic detergents have been associated with outbreaks of TASS. 3–5 continued on page 12