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Analysis of the microbiota in Goldmann applanation tonometers

ABSTRACT

Objective: Analyze the microbiota prevalence in the Goldmann applanation tonometers in the clinic of the SUS to define the contamination of the tonometers and the efficacy of asepsis of the applanation tonometer cone. Methods: A cross-sectional study was carried out to collect 60 “swabs” divided into the three aplanation tonometers of SUS clinics at two different times. In the first one, the collection will be performed at the beginning of the visits and at the second moment, the collection will be performed at the end of all the visits. All swabs will be harvested in the Stuart medium and culture was carried to sow bacteria. Results: Of the 60 samples, only one showed pathogen growth, Escherichia coli. Conclusion: Regardless of the various ways the ophthalmologist chooses to perform asepsis, it is essential for the maintenance of good patient eye health, thus avoiding the transmission and propagation of pathogens through ophthalmologic examination, and we also conclude that the method used by our patient seems to be effective in this prophylaxis.

Keywords:
Tonometer; Glaucoma; Microbiota

RESUMO

Objetivos: Analisar a prevalência da microbiota nos tonômetros de aplanação de Goldmann nos consultórios do SUS e definir o grau de contaminação dos tonômetros e a eficácia da assepsia do cone do tonômetro de aplanação. Métodos: Estudo transversal em que foi realizado a coleta de 60 “swabs”, divididos nos três tonômetros de aplanação dos ambulatórios do SUS em dois momentos distintos. No primeiro realizou-se a coleta no início dos atendimentos e no segundo momento, a coleta foi realizada ao final de todos os atendimentos. Todos “swabs” foram colhidos no meio Stuart e foi realizada a cultura em meio de bactérias. Resultados: Das 60 amostras, apenas uma apresentou crescimento de agente patogênico, a Escherichia coli. Conclusão: Independente dos vários métodos que o oftalmologista escolher para realizar a assepsia, a mesma é imprescindível para a manutenção de uma boa saúde ocular do paciente, evitando assim a transmissão e propagação de patógenos por meio do exame oftalmológico e concluímos também que o método utilizado pelo nosso serviço parece ser eficaz nesta profilaxia.

Descritores:
Tonômetro; Glaucoma; Microbiota

INTRODUCTION

Glaucoma is one of the main causes of irreversible blindness in the world. It is defined by irreversible optic neuropathy in which there is loss of ganglion cells and its main risk factor is increased intraocular pressure (IOP)(11 Resnikoff S, Pascolini D, Etya’ale D, Kocur I, Pararajasegaram R, Pokharel GP, et al. Global data on visual impairment in the year 2002. Bull World Health Organ. 2004;82(11):844-51.).

An individual’s IOP can be determined by means of Goldman’s aplanation tonometry, whose original technique was described in 1957 by Goldmann and Schimdt. It is based on the Imbert-Fick principle, in which the applied pressure (P) is equal to the force (F) required to flatten a surface divided by the applanation area (A) (P=F/A).(22 Goldmann H, Schmidt T. [Applanation tonometry]. Ophthalmologica. 1957;134(4):221-42. German.) Although there are several new techniques for evaluation, this remains the gold standard technique for IOP measurement.

In this sense, a plastic cone with two prisms is used, and the free end of which lies directly on the patient’s cornea, making it possible to measure.(33 Maimone N, Maimone AL. Avaliação de um novo produto na desinfecção do tonômetro de aplanação de Goldmann. Arq Bras Oftalmol. 2001;64(6):545-9.) The use of fluorescein for this is paramount,(44 Moses RA. Fluorescein in applanation tonometry. Am J Ophthalmol. 1960; 49:1149-55.) but it is not mandatory. Due to direct contact of the plastic cone with the cornea, it becomes potentially contaminated, since the conjunctival sac may contain bacteria and fungi,(55 Marcon AS, Barbosa MP, Vasques CL, Marcon IM, Dorneles IC, Kader IT, et al. Microbiota aeróbia e anaeróbia da conjuntiva e borda palpebral de indivíduos hígidos. Arq Bras Oftalmol. 1996;59(3):289-94.) and fluorescein may be contaminated with Pseudomonas aeroginosa.(66 Vaughan DG Jr. The contamination of fluorescein solutions; with special reference to pseudomonas aeruginosa (bacillus pyocyaneus). Am J Ophthalmol. 1955;39(1):55-61.,77 Vaughan DG, Taylor A, Riordan-Eva P. Oftalmologia geral. 4a ed. São Paulo: Atheneu; 1997.)

The objective of the present study was to analyze the prevalence and type of the microbiota in the Goldmann applanation tonometers to determine the degree of contamination of the tonometers, as well as the efficacy of the asepsis of the applanation tonometer cone.

METHODS

This is a cross-sectional study, and the collection was performed with swabs on the three aplanation tonometers in SUS ambulatories at two different times. At first, the collection was made at the beginning of the visits, in order to quantify the prevalence and type of the microbiota present in the tonometers. In the second moment, the measurement was made at the end of all the visits, so that the efficacy of the asepsis throughout the day and the change of the microbiota during the day could be analyzed.

All collections were carried out between November 13, 2017 and November 20, 2017, totaling 20 collection periods and 60 samples. The samples were separated into three groups, Offices I, II and III, which are divided according to the room where the tonometer is located.

All samples were collected by means of sterile swabs wrapped in Stuart’s medium, which conserve pathogenic microorganisms such as: Haemophilus spp., Pneumococcus, Salmonella spp., Shigella spp., among others.(88 Agência Nacional de Vigilância Sanitária (ANVISA). Descrição dos meios de cultura empregados nos exames microbiológicos. Modulo IV. [citado 2018 Abr 23]. Disponível em: http://www.anvisa.gov.br/servicosaude/manuais/microbiologia/mod_4_2004.pdf
http://www.anvisa.gov.br/servicosaude/ma...
) After 24 hours of collection the material was sent to the accredited laboratory to be seeded in a culture medium for bacteria, which occurred within 48 hours after collection. Before each collection, the apparatus was cleaned using paper tissues soaked in alcohol 70%, followed by friction at the patient’s contact location, from the head holder in the slit lamp to the Goldmann tonometer cone.

RESULTS

All the swabs of Office I and Office II did not show growth of bacteria. In Office III, Escherichia coli was only present in one sample resistant to ciprofloxacin and trimethoprim + sulfadiazine and sensitive to the other classes of antimicrobial agents. Such sample was obtained at the first moment, before the beginning of the consultations in the office (Table 1).

Table 1
Results of the cultures

DISCUSSION

There are several products for the asepsis of the Goldmann tonometer, which consist of water and soap, dry cotton, cotton with alcohol and serum, running water, cotton with antibiotic eyedrops, Soapex®, ultraviolet radiation, alcohol plus ether, germikil, shampoos, saline solution, Methiolate®, sodium hypochlorite 1%, hydrogen peroxide 3%, and contact lens products and ether.(99 Fedukowicz HB. External infections of the eye. 2nd ed. New York: Appleton-Century-Crofts; 1978.,1010 Gonçalves L. Assepsia do cone plástico do tonômetro de aplanação (como você limpa o seu?). Rev Bras Oftalmol. 1989;48(1):37-8.) There are also several hygiene modes, ranging from cone friction with cotton or wipe, to the immersion of the tonometer cone in aseptic solution.(33 Maimone N, Maimone AL. Avaliação de um novo produto na desinfecção do tonômetro de aplanação de Goldmann. Arq Bras Oftalmol. 2001;64(6):545-9.)

For optimal asepsis, the American Academy of Ophthalmology recommends the immersion of the cone for 5 to 10 minutes in a solution of hydrogen peroxide 3% or sodium hypochlorite 0.5% preceded by rinsing and drying.(1111 Netto AA, Amaro AC, Daguano CE. Avaliação da contaminação bacteriana dos cones de aplanação dos tonômetros de Goldmann em uso em consultórios e hospitais da Grande Florianópolis. Arq Catarinenses Med. 2007;36(1): 45-50.)

Our study showed that only one sample had bacterial culture, and this result is in accordance with the study of Netto et al.,(1111 Netto AA, Amaro AC, Daguano CE. Avaliação da contaminação bacteriana dos cones de aplanação dos tonômetros de Goldmann em uso em consultórios e hospitais da Grande Florianópolis. Arq Catarinenses Med. 2007;36(1): 45-50.) which also showed that most tonometers did not show growth of any pathogen.

However, our study differs from the others in relation to the pathogenic agent in the sample. In the studies of Netto et al.(1111 Netto AA, Amaro AC, Daguano CE. Avaliação da contaminação bacteriana dos cones de aplanação dos tonômetros de Goldmann em uso em consultórios e hospitais da Grande Florianópolis. Arq Catarinenses Med. 2007;36(1): 45-50.) and Norn et al.,(1212 Norn MS, Thomsen F. Contamination of applanation tonometer prism. Acta Ophthalmol (Copenh). 1968;46(4):712-20.) Staphylococcus sp coagulase negative was the most prevalent microorganism, whereas in our study we only obtained the growth of Escherichia coli and only in one isolated sample.

In our study, we used Stuart’s culture medium, which is considered the ideal for collection of material that took time to be sown(88 Agência Nacional de Vigilância Sanitária (ANVISA). Descrição dos meios de cultura empregados nos exames microbiológicos. Modulo IV. [citado 2018 Abr 23]. Disponível em: http://www.anvisa.gov.br/servicosaude/manuais/microbiologia/mod_4_2004.pdf
http://www.anvisa.gov.br/servicosaude/ma...
,1313 Nogueira DC, Ueda SM, Murça MA, Hida WT, Felberg S, Serruya L, et al. Comparação entre dois meios de coleta e transporte para estudo da microbiota conjuntival de indivíduos normais. Arq Bras Oftalmol. 2007;70(6):929-34.) and discarded any change due to poor use of the culture medium. It is known that for the viability of microorganism in the Stuart medium, it can wait until 72h for sowing,(1313 Nogueira DC, Ueda SM, Murça MA, Hida WT, Felberg S, Serruya L, et al. Comparação entre dois meios de coleta e transporte para estudo da microbiota conjuntival de indivíduos normais. Arq Bras Oftalmol. 2007;70(6):929-34.) and in our study sowing was made 48h after the material was collected.

As the swab presenting growth was the one from the first moment of collection, we believe that this result can demonstrate contamination of the sample, since this is not the normal conjunctival microbiota. The finding may also suggest that this bacterium was present in the conjunctival sac of the last patient attended the day prior to collection, showing a potential contamination if the correct asepsis of the tonometer is not performed.

CONCLUSION

Regardless of the various methods that the ophthalmologist has to perform asepsis, it is essential for the maintenance of good eye health of the patient, thus avoiding the transmission and propagation of pathogens through ophthalmologic examination. Finally, we conclude that the method used by our service seems to be effective in this prophylaxis

  • Research developed at Instituto de Olhos de Goiânia, Goiânia, GO, Brazil.

REFERÊNCIAS

  • 1
    Resnikoff S, Pascolini D, Etya’ale D, Kocur I, Pararajasegaram R, Pokharel GP, et al. Global data on visual impairment in the year 2002. Bull World Health Organ. 2004;82(11):844-51.
  • 2
    Goldmann H, Schmidt T. [Applanation tonometry]. Ophthalmologica. 1957;134(4):221-42. German.
  • 3
    Maimone N, Maimone AL. Avaliação de um novo produto na desinfecção do tonômetro de aplanação de Goldmann. Arq Bras Oftalmol. 2001;64(6):545-9.
  • 4
    Moses RA. Fluorescein in applanation tonometry. Am J Ophthalmol. 1960; 49:1149-55.
  • 5
    Marcon AS, Barbosa MP, Vasques CL, Marcon IM, Dorneles IC, Kader IT, et al. Microbiota aeróbia e anaeróbia da conjuntiva e borda palpebral de indivíduos hígidos. Arq Bras Oftalmol. 1996;59(3):289-94.
  • 6
    Vaughan DG Jr. The contamination of fluorescein solutions; with special reference to pseudomonas aeruginosa (bacillus pyocyaneus). Am J Ophthalmol. 1955;39(1):55-61.
  • 7
    Vaughan DG, Taylor A, Riordan-Eva P. Oftalmologia geral. 4a ed. São Paulo: Atheneu; 1997.
  • 8
    Agência Nacional de Vigilância Sanitária (ANVISA). Descrição dos meios de cultura empregados nos exames microbiológicos. Modulo IV. [citado 2018 Abr 23]. Disponível em: http://www.anvisa.gov.br/servicosaude/manuais/microbiologia/mod_4_2004.pdf
    » http://www.anvisa.gov.br/servicosaude/manuais/microbiologia/mod_4_2004.pdf
  • 9
    Fedukowicz HB. External infections of the eye. 2nd ed. New York: Appleton-Century-Crofts; 1978.
  • 10
    Gonçalves L. Assepsia do cone plástico do tonômetro de aplanação (como você limpa o seu?). Rev Bras Oftalmol. 1989;48(1):37-8.
  • 11
    Netto AA, Amaro AC, Daguano CE. Avaliação da contaminação bacteriana dos cones de aplanação dos tonômetros de Goldmann em uso em consultórios e hospitais da Grande Florianópolis. Arq Catarinenses Med. 2007;36(1): 45-50.
  • 12
    Norn MS, Thomsen F. Contamination of applanation tonometer prism. Acta Ophthalmol (Copenh). 1968;46(4):712-20.
  • 13
    Nogueira DC, Ueda SM, Murça MA, Hida WT, Felberg S, Serruya L, et al. Comparação entre dois meios de coleta e transporte para estudo da microbiota conjuntival de indivíduos normais. Arq Bras Oftalmol. 2007;70(6):929-34.

Publication Dates

  • Publication in this collection
    Jul-Aug 2018

History

  • Received
    31 Jan 2018
  • Accepted
    19 May 2018
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