Disinfection of Eyelid Speculums for Retinopathy of Prematurity Examination

CLINICAL SCIENCES Disinfection of Eyelid Speculums for Retinopathy of Prematurity Examination

Troy J. Woodman, MD; David K. Coats, MD; Evelyn A. Paysse, MD; Gail J. Demmler, MD; Susan N. Rossmann, MD, PhD

Objective: To evaluate the effectiveness of 70% isopro- cleaned group yielded bacteria compared with 21 (95.5%) pyl alcohol swabs in disinfecting eyelid speculums after of 22 controls. Fungi were isolated from only 1 control examination for retinopathy of prematurity . and from no cleaned speculums. Phase 2: all speculums inoculated with adenovirus supported growth of the or- Methods: Two phases. Phase 1: 46 autoclave-sterilized ganism irrespective of cleaning with 70% isopropyl al- eyelid speculums randomized into either a cleaned or con- cohol swabs. None of 5 cleaned speculums inoculated trol group following examination for retinopathy of pre- with herpes simplex virus type 2 supported viral growth, maturity. Speculums in the cleaned group were disin- compared with 3 (60%) of 5 cultures positive for growth fected with a 70% isopropyl alcohol swab while control in the control group. speculums were not cleaned. Bacterial and fungal cultures were then obtained. Phase 2: 20 autoclave- Conclusion: Cleaning eyelid speculums with 70% iso- sterilized eyelid speculums inoculated with a clinically propyl alcohol swabs provided inadequate disinfection relevant dilution of adenovirus serotype 5 or herpes sim- against bacteria following examination for retinopathy plex virus type 2. Inoculated speculums were random- of prematurity and against adenovirus in a laboratory ized into either a cleaned or control group. simulation.

Results: Phase 1: 17 (70.8%) of 24 cultures from the Arch Ophthalmol. 1998;116:1195-1198

T MOST centers, examina- RESULTS tions for retinopathy of prematurity (ROP) are per- PHASE 1 formed sequentially on multiple patients in a neo- Seventeen (70.8%) of 24 cultures in the Anatal intensive care unit setting. A reus- cleaned group demonstrated microbial able metallic eyelid speculum is often used growth whereas 21 (95.5%) of 22 cul- to facilitate examination and enhance di- tures in the control group showed agnostic accuracy,1 followed by thorough growth (PϽ.O5) (Figure 1). Of the cul- cleaning between patients. Cleaning meth- tures positive for organisms in the ods available include wiping with 70% iso- cleaned group, 16 yielded coagulase- propyl alcohol or Betadine swabs, soaking negative Staphylococcus (CONS); and 1, in hydrogen peroxide or 70% isopropyl al- Bacillus cereus (Figure 2). No fungus cohol, and autoclave sterilization. Because grew in any of the cultures from the premature infants are immunocompro- cleaned group. The organisms grown in mised and at high risk for life-threatening the control group were considerably infection,2 it is important to assure that more varied and contained not only cleaning methods used are satisfactory. This CONS and Bacillus species, but also From the Departments of study was designed to evaluate the effec- methicillin-resistant Staphylococcus Ophthalmology, Cullen Eye tiveness of cleaning speculums with 70% aureus, Enterococcus, and multiple gram- Institute (Drs Woodman, Coats, isopropyl alcohol swabs against bacteria, negative rods (Figure 2). One control and Paysse), Pediatrics and Pathology (Dr Demmler), and fungi, and 2 viruses. This particular clean- speculum yielded fungus (Candida albi- Pathology (Dr Rossmann), ing method was chosen because it is com- cans). All cultures obtained from specu- Baylor College of Medicine, monly used, readily available, and has been lums cleaned immediately after removal Texas Children’s Hospital, demonstrated to be effective in cleaning from the sterile packaging were negative Houston. other ophthalmic instruments. for organisms.

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©1998 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/30/2021 METHODS using standard laboratory methods. After the incubation period, a Gram stain was done on each broth to detect any organisms not previously recovered. The Fisher exact test PHASE 1 was used for statistical analysis. This protocol adhered to the Declaration of Helsinki. Forty-six autoclave-sterilized Alfonso pediatric eyelid speculums (Storz Inc, Ophthalmic Instrumentation Division, PHASE 2 Cleveland, Ohio) were randomized into a cleaned or control group following examinations for ROP in the neo- Stock strains of adenovirus serotype 5 and herpes simplex natal intensive care unit. Using sterile gloves, the exam- virus type 2 (HSV-2) were grown in cell culture and di- iner (D.K.C. or E.A.P.) placed a sterile speculum within luted in minimal essential media to 10−3 log virus, which the eyelids of a neonate and performed indirect ophthal- was thought to be a clinically relevant titer of virus and com- moscopy with scleral depression in the usual manner of ex- parable to other studies of viral disinfection.4,5 Ten eyelid amination for ROP .3 To minimize possible contamination speculums were assigned to each of the 2 viruses. The ster- by the examiner, a separate pair of sterile gloves was used ile speculums were then immersed in their respective vi- to remove the speculum. Speculums in the cleaned group ral suspensions for 1 minute. Using sterile forceps and were cleaned thoroughly with a 70% isopropyl alcohol gloves, the speculums were removed, separated, and placed preparation pad (Webcol, Kendall Co, Mansfield, Mass) for on a sterile platform. Five speculums from each group were 10 seconds and allowed to air dry. An attempt was made randomly chosen as controls and allowed to air dry under to clean all surfaces of the speculums. Each speculum was a biologic safety cabinet and fluorescent lighting. The re- then transferred in a sterile manner to a 100-mL sterile con- maining speculums from each group were thoroughly tainer that held 10 mL of trypticase soy broth with 5% Fildes swabbed with a 70% isopropyl alcohol pad for 10 seconds Enrichment (Becton Dickinson Microbiology Systems, and allowed to air dry. Separate sterile forceps were used Cockeysville, Md), which completely covered the instru- to transfer each speculum to individual containers of viral ment. Speculums in the control group were allowed to air transport media sufficient for its immersion. Meticulous ster- dry and then placed in identical containers without clean- ile technique was maintained to prevent contamination. The ing. Last, 5 sterile, unused speculums were cleaned in the solution was then agitated and a 0.2-mL aliquot of media above fashion immediately after removal from the sterile was removed from each container and inoculated onto cell packaging, allowed to air dry, and placed into the culture culture monolayers of human foreskin fibroblasts, rhesus media to test for possible contamination inherent to the monkey kidney, and A549 cells. The inoculum was al- cleansing technique itself. lowed to adsorb for 4 hours, washed, and refed with me- The speculums were then incubated at 35°C in 5% to dia. The cell cultures were incubated on a roller drum in a 10% carbon dioxide and observed for 7 days. If the broth warm airflow incubator at 37°C, observed daily for cyto- became turbid during the 7- day incubation period, a Gram pathic effect, and the results recorded. Preliminary iden- stain was performed and the broth was inoculated to tryp- tification of each virus was by cytopathic effect with con- ticase soy agar II with 5% SRBC, chocolate II agar, and Mac- firmation by immunoflourescence assay, using an adenovirus Conkey II agar (all from Becton Dickinson Microbiology monoclonal antibody reagent (Bartels, Inc, Issaquah, Wash). Systems). Organisms were then isolated and identified The Fisher exact test was used for statistical analysis.

PHASE 2 lenses, etc, can be sufficiently cleaned using an alcohol swab technique.8 These findings and practices may en- Five (100%) cleaned and 5 (100%) control speculums courage practitioners to use this cleaning technique for inoculated with adenovirus serotype 5 were positive for eyelid speculums following examination for ROP. How- the virus (Figure 3). No cultures positive for organ- ever, important differences between the instruments to isms were found in the HSV-2 group after cleaning, while be cleaned and the patient populations make direct 3 (60%) of 5 controls were positive for organisms (P = 1.7). comparisons problematic. For instance, there is a fun- damental difference in the shape and configuration of COMMENT an eyelid speculum compared with a Goldmann tonometer tip. An eyelid speculum is bent in several places, Examinations for ROP are often performed sequentially making much of its surface difficult to clean with a on multiple infants. Equipment that comes into contact swab, whereas a Goldmann tonometer tip has a flat ap- with the infants during examination must be ad- planation surface making the entire contact area readily equately disinfected between examinations to eliminate amenable to swabbing (Figure 4). the risk of transmission of iatrogenic infectious disease. Additionally, a cleaning technique that is adequate Several recent studies have demonstrated that Gold- for instruments used on healthy adults may not be mann tonometer tips can be adequately disinfected with adequate for instruments used on premature infants. Neo- an alcohol swab against adenovirus,4,5 HSV, and human nates at risk for ROP are typically immunocompro- immunodeficiency virus.6 Corboy and Borchardt7 found mised and commonly exhibit extremely low birth weight, certain bacteria inoculated onto tonometer tips to be sus- and such infants are at significantly increased risk for ceptible to simply wiping with a dry tissue. Many non- life-threatening infections.9 Organisms often disre- surgical examination instruments, such as Goldmann garded as “normal flora” in healthy patients can be dev- tonometer tips, Schio¨tz tonometers, diagnostic contact astating to the premature infant. For instance, CONS, a

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60 60 65% Percent Percent 40 40

20 20

0% 0 0 Control Cleaned Control Cleaned

Figure 1. Growth rates for phase 1 (bacterial and fungal). Despite cleaning, Figure 3. Growth rates for phase 2 (viral). Ten (100%) speculums grew bacteria were cultured from 17 cleaned speculums (70.8%). adenovirus irrespective of cleaning. Herpes simplex virus type 2 was effectively eliminated.

Bacillus cereus No Growth (4.5%) Other Gram-negative (4.2%) Rods (4.5%) No Growth MRSA (4.5%) Enterobacteriaceae (29.2%) (18.2%) Candida (4.5%) CONS (66.7%) Enterococcus (22.7%) B cereus (4.5%) CONS (36.4%)

Figure 2. Comparison of organisms cultured from phase 1 (bacterial and fungal) cleaned group (left), and control group (right). MRSA indicates Figure 4. An Alfonso eyelid speculum (left) and a Goldmann tonometer tip methicillin-resistant Staphylococcus aureus; CONS, coagulase-negative (right). Design properties of each instrument probably explain differences in Staphylococcus. efficacy of 70% isopropyl alcohol disinfection.

common environmental organism,10 was responsible for Cleaning with 70% isopropyl alcohol swabs proved as many as 49% of the cases of neonatal sepsis in 2 ma- completely ineffective against adenovirus serotype 5 in jor centers.11,12 Coagulase-negative Staphylococcus can also our laboratory simulation. The prolonged survival of ad- cause other life-threatening infections in this popula- enovirus has been previously demonstrated on inor- tion, including meningitis, pneumonia, and endocardi- ganic surfaces and some investigators have recovered this tis, as well as ocular infections such as conjunctivitis, kera- organism from plastic and metal surfaces as long as 1 to titis, and endophthalmitis. Our data demonstrate that 7 weeks after inoculation.15,16 Nevertheless, the poor per- cleaning an Alfonso eyelid speculum with a 70% isopro- formance of this cleaning technique on eyelid specu- pyl alcohol swab is ineffective against this organism, as lums was surprising, as others have clearly demon- more than two thirds of the cleaned speculums yielded strated alcohol wipes to be quite effective against cultures positive for CONS. Not only does the design of adenovirus on Goldmann tonometer tips.4,5 This differ- the speculum render cleaning difficult, but CONS- ence is most likely because of the structural design dif- related factors may also contribute to problems associ- ferences of the 2 instruments. The clinical relevance of ated with this method of disinfection. Certain strains of these findings is apparent when one considers that ad- Staphylococcus epidermidis, a commonly isolated mem- enovirus not only causes keratoconjunctivitis, but it can ber of the CONS family, produce a mucoid substance, produce severe pneumonia and enteritis with potential or slime, that makes the bacteria highly adhesive.13,14 life-threatening complications in the neonatal popula- This material may allow organisms to more firmly tion. Our data on HSV-2 corresponds well with Gold- adhere to regions on the speculum that are difficult to mann tonometer data.6 The higher kill rate for HSV-2 may clean with an alcohol pad. be related to the fact that this virus is enveloped and there- Fungal (yeast) growth was confirmed in only 1 cul- fore more susceptible to the disinfectant properties of iso- ture of the control group and in none of the cleaned specu- propyl alcohol.17 lums. Fildes Enrichment was used to fortify the culture In summary, cleaning Alfonso pediatric eyelid specu- broth in an effort to promote the growth of any fungal lums with 70% isopropyl alcohol swabs was ineffective organisms adherent to the speculums, but the low fun- in disinfecting them against potentially dangerous bac- gal growth rate in both the control and cleaned groups teria in a clinical study and ineffective against adenovi- does not allow for conclusions about fungal growth to rus in a laboratory simulation. These organisms not only be made. pose a serious threat to vision but have the potential to

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©1998 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/30/2021 cause serious systemic disease in the population at risk 3. Palmer EA, Flynn JT, Hardy RJ, et al. Incidence and early course of retinopathy for ROP. Although we have not attempted to demon- of prematurity. Ophthalmology. 1991;98:1628-1640. 4. Threlkeld AB, Froggatt III JW, Schein OD, Forman MS. Efficacy of a disinfectant strate an increase in actual infection rates, the mere pres- wipe method for the removal of adenovirus 8 from tonometer tips. Ophthalmol- ence of these organisms on cleaned speculums warrants ogy. 1993;100:1841-1845. discontinuation of this particular cleaning method for eye- 5. Craven ER, Butler SL, McCulley JP, Luby JP. Applanation tonometer tip steril- lid speculums used during examinations for ROP. We rec- ization for adenovirus type 8. Ophthalmology. 1987;94:1538-1540. 6. Pepose JS, Linette G, Lee SF, MacRae S. Disinfection of Goldmann tonometers ommend the use of a new or autoclave-sterilized specu- against human immunodeficiency virus type 1. Arch Ophthalmol. 1989;107:983- lum on each patient examined for ROP and discourage 985. the use of other common cleaning methods until their 7. Corboy JM, Borchardt KA. Mechanical sterilization of the applanation tonom- efficacy against bacteria, fungi, and viruses has been dem- eter, 1: bacterial study. Am J Ophthalmol. 1971;71:889-891. onstrated in a controlled study. 8. American Academy of Ophthalmology, National Society to Prevent Blindness, Con- tact Lens Association of Ophthalmologists. Clinical Alert 2/4: updated recom- mendations for ophthalmic practice in relation to the human immunodeficiency Accepted for publication June 5, 1998. virus. Ophthalmology. 1989;96:1ff. This study was supported in part by a grant from Re- 9. Vesikari T, Janas M, Gronroos P, et al. Neonatal septicaemia. Arch Dis Child. 1985; search to Prevent Blindness Inc, New York, NY (Drs Coats 60:542-546. 10. Munson DP, Thompson TR, Johnson DE, Rhame FS, VanDrunen N, Ferrieri P. and Paysse), and an Everett L. Goar resident award from Coagulase-negative staphylococcal septicemia: experience in a newborn inten- the Cullen Eye Institute, Baylor College of Medicine, Hous- sive care unit. J Pediatr. 1982;101:602-605. ton, Tex (Dr Woodman). 11. Hensey OJ, Hart CA, Cooke RWI. Serious infection in a neonatal intensive care Presented as a poster at the American Association of unit: a two-year survey. J Hyg (Cambridge). 1985;95:289-297. 12. Baumgart S, Hall SE, Campos JM, Polin RA. Sepsis with coagulase-negative staphy- Pediatric Ophthalmology and Strabismus Annual Meeting, lococci in critically ill newborns. AJDC. 1983;137:461-463. Palm Springs, Calif, April 7, 1998. 13. Tojo M, Yamashita N, Goldmann DA, Pier GB. Isolation and characterization of a Reprints: David K. Coats, MD, Texas Children’s Hos- capsular polysaccharide adhesin from Staphylococcus epidermidis. J Infect Dis. pital, 1102 Bates, Suite 300, MC 3-2700, Houston, TX 77030 1988;157:713-722. (e-mail: [email protected]). 14. Christensen GD, Simpson WA, Bisno AL, Beachey EH. Adherence of slime- producing strains of Staphylococcus epidermidis to smooth surfaces. Infect Im- mun. 1982;37:318-326. REFERENCES 15. Gordon YJ, Gordon RY, Romanowski E, Araullo-Cruz TP. Prolonged recovery of desiccated adenoviral serotypes 5,8, and 19 from plastic and metal surfaces in vitro. Ophthalmology. 1993;100:1835-1840. 1. Dhillon B, Wright E, Fleck BW. Screening for retinopathy of prematurity: are a lid 16. Hara J, Okamato S, Minekawa Y, Yamazaki K, Kase T. Survival and disinfection speculum and scleral indentation necessary? J Pediatr Ophthalmol Strabismus. of adenovirus type 19 and enterovirus 70 in ophthalmic practice. Jpn J Ophthal- 1993;30:377-381. mol. 1990;34:421-427. 2. Klein JO, Marcy SM. Bacterial sepsis and meningitis. In: Remington JS, Klein 17. Klein M, Deforest A. Virucidal activity of disinfection. In: Russell AD, Hgo WB, JO, eds. Infectious Diseases of the Fetus and Newborn Infant. Philadelphia, Pa: Ayliffe, GAJ. Principles and Practice of Disinfection, Preservation and Steriliza- WB Saunders Co; 1995:836-890. tion. 2nd ed. Oxford, Enlgand: Blackwell Scientifc ublications; 1992:150-170.

100 Years Ago in the ARCHIVES

A look at the past...

his report of BURNETT is that which was sent to Chibret as chairman of the committee appointed by the French Ophthalmological Society to collect statistics on trachoma. Letters of inquiry were sent to various oculists in all Tregions of the United States, asking their observation as to the frequency of trachoma among different races, the effect of altitude, employment, contagiuosness, etc., a distinction being made between true trachoma and follicular conjunctivitis. Thirteen answers were received, which are printed in full. The conclusions which Burnett draws from the informa- tion thus furnished is that in the United States altitude seems to exercise but little influence on the frequency of the disease. The Jew, the Irish, and Italians are greatest sufferers, though the American of the central region of southeastern Kentucky, West Virginia, and North Carolina forms an important element in the statistics both as to frequency and virulency. The ne- gro is reported as being practically immune even in communities where the disease is very prevalent among the white. Opin- ions are divided as to contagiousness.

Reference: Arch Ophthalmol. 1897;26:296.

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