January 2016




ASCRS, AAO, and OOSS release joint recommendations on the use of enzyme detergents to clean intraocular surgical instruments

by Liz Hillman EyeWorld Staff Writer


With more CMS surveyors enforcing the use of controversial enzymatic cleaners, 3 key societies jointly issue guidelines to support ASCs that choose not to use them due to TASS risk

The American Society of Cataract & Refractive Surgery (ASCRS), along with the American Academy of Ophthalmology (AAO) and the Ophthalmic Outpatient Surgery Society (OOSS), have jointly published clinical guidelines for ambulatory surgery centers (ASCs) regarding the use of enzyme detergents to clean intraocular surgical instruments. ASCRS and the American Society of Ophthalmic Registered Nurses (ASORN) first produced recommendations on instrument cleaning and sterilization in 2007 after a nationwide outbreak of toxic anterior segment syndrome (TASS). The ASCRS TASS Task Force followed up with studies published in 2010 and 2012 that linked residual enzyme detergentsoften included as a cleaning measure in manufacturers instructions for useon instruments to an increased risk of TASS. More recently, a joint ASCRS, AAO, and OOSS survey of ophthalmic ASCs revealed that roughly half used and half did not use enzymatic cleaner for intraocular instruments, with no difference in reported infection rates. In light of both the survey and the studies, the ASCRS/AAO/OOSS Task Force on instrument cleaning and sterilization, chaired by David F. Chang, MD, and Nick Mamalis, MD, decided to issue a clinical guideline on this matter of enzymatic cleaner. Dr. Mamalis previously chaired the ASCRS TASS Task Force. Weve seen that Center for Medicare and Medicaid Services (CMS) surveyors now appear to be requiring enzyme detergent cleaning of intraocular instruments according to manufacturers recommendations, Dr. Chang said. However, we think that forcing ASCs to newly institute enzymatic cleaning could be a recipe for TASS outbreaks. While enzyme detergent is useful for removing caked blood or dried tissue debris, intraocular instruments do not accumulate this degree of biofilm and can be effectively cleaned with prompt rinsing and a soft brush. Dr. Chang explained the urgency of issuing this guideline once the committee became aware of ASCs being required to institute enzyme use. Many ophthalmologists who have never seen or managed TASS cases may misdiagnose these inflamed eyes as infectious endophthalmitis. If referred to vitreoretinal surgeons as a precaution, the latter 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 potentially blinding infection. By issuing this clinical guideline, Dr. Chang said ASCRS is committed to educating ophthalmologists and their ASC staff on the potential risk of using enzymatic cleaners with an unproven endophthalmitis benefit and defending ASCs who choose not to use enzymes routinely because of these TASS risks. We have sent these clinical guidelines to CMS with the hope of better educating their surveyors about the unintended risk to patients 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 potentially sight threatening complications of cataract and other intraocular surgeries. Particularly because of the high frequency of cataract surgery, improper instrument cleaning practices pose a significant risk to patients. Because of conflicting guidelines, one practice that is controversial and of concern to regulatory agencies is the use of enzymatic detergents for decontaminating intraocular surgical instruments. The manufacturers instructions for use (IFU) that accompanies ophthalmic 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 established. Contrary to some manufacturers 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 amylase, 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.35 The purpose of enzymatic detergent 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 cleaning. Even minute enzyme residue left on intraocular instruments can cause TASS, and the small diameter lumens and fragile nature of intraocular instruments makes complete removal of all traces of detergent difficult. Therefore, enzymatic detergents 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: 20072009 and 20092012.4,5 Data from 130 questionnaires 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 common risk factors for TASS included inadequate flushing of handpieces, use of enzyme detergents, and use of ultrasound baths.5 Based on the published ASCRS TASS Task Force findings, we conclude that if intraocular surgical instruments are thoroughly rinsed with sterile distilled or deionized 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 bacteria 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 common practice among ASCs. In 2014, a survey developed by ASCRS, AAO, and OOSS was sent to OOSS member ophthalmic single specialty ASCs regarding cleaning and sterilization of intraocular instruments. Complete responses were received from 182 ASCs. A majority (55.5%) did not use enzyme for intraocular instrument decontamination, compared with 44.5% who did. The average self-reported rate of endophthalmitis was 0.021% for non-enzyme-using facilities compared to 0.027% for enzyme-using facilities. We are not aware of a study demonstrating that enzyme detergent for intraocular instruments reduces the rate of endophthalmitis. Based on the documented risk of TASS associated with enzyme detergent use, without proven benefit for endophthalmitis prevention, enzymatic detergent should not be required for routine decontamination of ophthalmic intraocular instruments.


1. Nuyts RM, Edelhauser HF, Pels E, Breebaart AC. Toxic effects of detergents on the corneal endothelium. Arch Ophthalmol. 1990;108:11581162. 2. Parikh C, Sippy BD, Martin DF, Edelhauser HF. Effects of enzymatic sterilization detergents on the corneal endothelium. Arch Ophthalmol. 2002;120:165172. 3. Mamalis N, Edelhauser HF, Dawson DG, Chew J, LeBoyer RM, Werner L. Toxic anterior segment syndrome. J Cataract Refract Surg. 2006;32:324333. 4. Cutler-Peck CM, Brubaker J, Clouser S, Danford C, Edelhauser HF, Mamalis N. Toxic anterior segment syndrome: common causes. J Cataract Refract Surg. 2010;36:10731080. 5. Bodnar Z, Clouser S, Mamalis N. Toxic anterior segment syndrome: Update on the most common causes. J Cataract Refract Surg. 2012;38:19021910.

Editors note: These recommendations are provided for information and educational use only. They are not intended to establish a standard of care or dictate a particular course of treatment. ASCRS members and other physicians must exercise their independent medical judgments in making treatment decisions for their patients.

Contact information

: dceye@earthlink.net

ASCRS, AAO, and OOSS release joint recommendations on the use of enzyme detergents to clean intraocular surgical instruments ASCRS, AAO, and OOSS release joint recommendations on the use of enzyme detergents to clean intraocular
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