Copyright 1998 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.1998American Medical AssociationThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
During JANUARY 8-14, 1998, six of eight patients undergoing elective intraocular surgery at a Veterans Affairs medical center (VAMC) in St. Louis, Missouri, developed corneal endothelial decompensation (corneal edema and opacification) ≤24 hours after surgery. All had been operated on with instruments sterilized by the Abtox Plazlyte system (Abtox, Inc., Chicago, Illinois).1 This report summarizes the results of the investigation of these cases and indicates that using the Abtox Plazlyte system to sterilize opthalmologic surgical equipment led to corneal decompensation.
A case was defined as corneal endothelial decompensation within 24 hours after surgery in any patient undergoing intraocular ophthalmic surgery during January 5-14, 1998. To ascertain cases and to determine the background rate of corneal decompensation, medical records of patients undergoing ophthalmic surgery during September 1997-January 1998 were reviewed. Six cases were identified. All patients had post-operative findings of persistent low visual acuity, cloudy corneas with corneal endothelial decompensation, and iris paralysis with dilated pupils. All were male, ranged in age from 43 to 85 years (median: 67 years), and had chronic systemic diseases such as coronary artery disease and hypertension. Four patients had cataract extraction and a posterior chamber intraocular lens implant, one had repositioning of a previously implanted anterior chamber intraocular lens that had become dislocated, and one had a trabeculectomy filtering procedure for glaucoma. All had surgery performed in the same operating room. The duration of surgery ranged from 17 minutes to 3.5 hours (median: 1.5 hours). Post-operative vision (range: 20/400 to Hand Motion) was significantly worse than pre-operative vision (range: 20/40-20/200).
When case-patients were compared with six randomly selected controls who underwent surgery during January 5-14 and did not have corneal decompensation, there were no differences in type of ophthalmic surgery performed; medications used before, during, or after surgery; type of local or general anesthesia; surgeons or anesthesiologists; or scrub and circulating nurses.
All instruments used in procedures on the case-patients and controls had undergone Abtox Plazlyte sterilization.1 In November 1997, the hospital discontinued using ethylene oxide to sterilize instruments used in ophthalmic surgery and began using the Abtox Plazlyte sterilization method.1,2 From November 5, 1997, through January 14, 1998, a total of 49 patients had ophthalmic surgery that involved instruments sterilized in the Abtox Plazlyte machine. This method uses a vaporized mixture of peracetic acid, acetic acid, and hydrogen peroxide in combination with low temperature.1,2 The vapor is removed with argon, oxygen, and hydrogen gas.1,2 The Abtox Plazlyte system has not been cleared by the Food and Drug Administration (FDA) for either safety or performance. An earlier design was cleared by FDA for use only on stainless steel instruments without small hinges are small lumens, but it was never distributed by Abtox. Instruments routinely used in ophthalmic surgery often have small hinges and small lumens. In addition, ophthalmic cannulas (small-lumen instruments) may have nickel- and chrome-plated brass hubs. Brass can be oxidized to yield copper and zinc compounds. Preliminary results using inductively coupled plasma atomic emission spectrometer analyses performed at CDC revealed copper and zinc in water rinsed through cannulas sterilized in the Abtox Plazlyte system. When this rinsate was infused into human and rabbit corneas, corneal decompensation occurred. Further laboratory testing is under way.
On January 14, 1998, the use of the Abtox system was discontinued at the St. Louis VAMC, and ophthalmic instruments were sterilized by steam autoclave. No additional cases have occurred. Abtox is conducting a field correction of the device that includes revised labeling that contraindicates use for ophthalmic instruments.
A Lubniewski, MD, S Sides, C Fisher, A Tess, MPH, T Lewis, L Kuhn, R Lusk, MD, Veterans Affairs Medical Center, St. Louis, Missouri; D Donnell, MD, D Dodson, Missouri Dept of Health. H Edelhauser, PhD, N Anderson, MD, Dept of Ophthalmology, Emory Univ, Atlanta, Georgia. Hospital Infections Program, National Center for Infectious Diseases; Div of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health; Div of Environmental Health Laboratory Sciences, National Center for Environmental Health; and EIS officers, CDC.
Corneal endothelial decompensation is manifested by opacity of the cornea; it can be a nonspecific response to mechanical or chemical injury.3 Mechanical trauma can result from incidental corneal contact by intraocular instruments during surgery; chemical injury can result from the improper use of intraocular drugs, drugs containing preservatives, or from residues from inadequate rinsing of detergents or other residues from surgical instruments.3,4 When severe, corneal endothelial decompensation requires corneal transplantation. Of the estimated 1.4 million cataract surgeries performed in the United States each year,5 <0.05% are complicated by corneal endothelial decompensation (A. Lubniewski, Veterans Affairs Medical Center, St. Louis, Missouri; and H. Edelhauser, Emory University, Atlanta, Georgia, personal communication, 1998).
Steam autoclaving is the preferred method for sterilizing surgical instruments. Ethylene oxide sterilization can be used for heat-sensitive items. However, because of the environmentally harmful effects of ethylene oxide, the Environmental Protection Agency encourages health-care providers to reduce the use of this form of sterilization. CDC's National Institute for Occupational Safety and Health considers ethylene oxide to be an occupational carcinogen and reproductive toxin.6,7 Since the early 1990s, new types of sterilization using plasma gas technology, such as the Abtox Plazlyte system, have been introduced.1,2 The inductively coupled plasma atomic emission data obtained from the CDC laboratory analyses, in part, prompted the FDA to issue a safety alert about the use of the Abtox Plazlyte Sterilization system to sterilize ophthalmic instruments.8
To ascertain the extent of this problem, all episodes of corneal decompensation following ophthalmic surgery and information about type of sterilization method used should be reported through state health departments to CDC's Hospital Infections Program, National Center for Infectious Diseases, telephone (404) 639-6413, and to FDA's MedWatch, telephone (800) 332-1088.
Corneal Decompensation After Intraocular Ophthalmic Surgery—Missouri, 1998. JAMA. 1998;279(23):1859-1860. doi:10.1001/jama.279.23.1859-JWR0617-3-1