Skip to main content

Advertisement

SpringerLink
Log in

Does the surface property of a disposable applanation tonometer account for its underestimation of intraocular pressure when compared with the Goldmann tonometer?

  • Laboratory Investigation
  • Published:
Graefe's Archive for Clinical and Experimental Ophthalmology Aims and scope Submit manuscript

Abstract

Background

Disposable tonometers are increasingly being adopted partly because of concerns over the transmission of variant Creutzfeldt-Jakob disease and partly for convenience. Recently, we have found one such tonometer (Tonojet by Luneau Ophthalmologie, France) underestimated the intraocular pressure (IOP).

Methods

We hypothesized that this underestimation was caused by a difference in the surface property of the tonometers. A tensiometer was used to measure the suction force resulting from interfacial tension between a solution of lignocaine and fluorescein and the tonometers.

Results

The results showed that the suction force was significantly greater for the Goldmann compared to the Tonojet.

Conclusions

The magnitude of this force was too small to account for the difference in IOP measurements. The Tonojet was less hydrophilic than the Goldmann, and the contact angle of the fluid was therefore greater. For a given tear film, less hydrophilic tonometers will tend to have thicker mires, and this may lead to underestimation of the IOP. When such disposable tonometers are used, it is recommended care should be taken to reject readings from thick mires.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1-1 Fig. 1-2
Fig. 2-1
Fig. 3

Similar content being viewed by others

Notes

  1. This is a 2% sodium hypochlorite solution. The active ingredients include sodium hypochlorite 2% w/w and sodium chloride 16.5% w/w.

  2. As measured by Vernier calipers.

References

  1. Baddon ACJ, Osborne S, Quah SA, Batterbury M, Wong D. Comparison of Luneau SA Disposable and Goldmann Applanation Tonometer readings. Eye. DOI EYE-05-423R

  2. Bhatnagar A, Gupta AK (2005) Disposable devices for measuring intraocular pressure: a clinical study to assess their accuracy. Eye 19:752–754

    Article  PubMed  CAS  Google Scholar 

  3. Desai SP, Sivakumar S, Fryers PT (2001) Evaluation of a disposable prism for applanation tonometry. Eye 15:279–282

    PubMed  CAS  Google Scholar 

  4. Kim P, Lertsumitkul S, Clark M, Gardner L, Macken P (2004) Accuracy of the Tonosafe disposable tonometer head compared to the Goldmann tonometer alone. Clin Experiment Ophthalmol 32:364–367

    Article  PubMed  Google Scholar 

  5. Liu C, Brown NND, Meenan BJ (2005) Statistical analysis of the effect of dielectric barrier discharge (DBD) operating parameters on the surface processing of poly(methylmethacrylate) film. Surface Sci 575:273–286

    Article  CAS  Google Scholar 

  6. Maldonado MJ, Rodriguez-Galietero A, Cano-Parra J, Menezo JL, Diaz-LLopis M (1996) Goldmann applanation tonometry using sterile disposable silicone tonometer shields. Ophthalmology 103:815–821

    PubMed  CAS  Google Scholar 

  7. Schmalenburg KE, Buettner HM, Uhrich KE (2004) Microprinting of proteins on oxygen plasma-activated poly(methylmethacrylate). Biomaterials 25:1851–1857

    Article  Google Scholar 

  8. Whitacre MM, Stein R (1993) Sources of error with use of Goldmann-type tonometers. Surv Ophthalmol 38(1):1–30

    Article  PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. St. Paul’s Ophthalmology Unit, Royal Liverpool University Hospital, Prescot Street, Liverpool, L7 8XP, UK

    Sarah F. Osborne, Mark Batterbury & David Wong

  2. Department of Clinical Engineering, School of Clinical Sciences, University of Liverpool, Liverpool, L7 8XP, UK

    Rachel Williams

Authors
  1. Sarah F. Osborne
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Rachel Williams
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Mark Batterbury
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. David Wong
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to David Wong.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Osborne, S.F., Williams, R., Batterbury, M. et al. Does the surface property of a disposable applanation tonometer account for its underestimation of intraocular pressure when compared with the Goldmann tonometer?. Graefe's Arch Clin Exp Ophthalmol 245, 555–559 (2007). https://doi.org/10.1007/s00417-006-0380-9

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00417-006-0380-9

Keywords

Search

Navigation