Article Text

Download PDFPDF
Diagnostic value of culture results from aqueous tap versus vitreous tap in cases of bacterial endophthalmitis
  1. Abdulrahman F AlBloushi1,2,
  2. Sofia Ajamil-Rodanes1,
  3. Ilaria Testi1,
  4. Catherine Wagland1,
  5. Nadine Grant-McKenzie1,
  6. Carlos Pavesio1
  1. 1Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and Biomedical Research Centre, Institute of Ophthalmology, UCL, London, UK
  2. 2Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
  1. Correspondence to Professor Carlos Pavesio, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; c.pavesio{at}nhs.net

Abstract

Objective To investigate the concordance between aqueous and vitreous tap culture results among different types of bacterial endophthalmitis.

Methods and analysis This retrospective cohort analysis included all cases diagnosed with endophthalmitis at Moorfields Eye Hospital between January 2008 and March 2020. Aqueous and vitreous samples obtained simultaneously at presentation. Samples were evaluated for sensitivity, specificity, negative and positive predictive values.

Results A total of 217 patients (217 eyes) were included in the study. Postsurgical endophthalmitis was the most common type of endophthalmitis and diagnosed in 35.9% of the cases. The rate of positive culture results was 32.2% from vitreous tap and 21.7% from aqueous tap. The culture yield through vitreous sampling was 15.7% when aqueous culture results were negative, and in 5.1%, the aqueous sample was positive when the vitreous tap results were negative. Considering the vitreous tap as the gold standard, aqueous sample culture results showed a statistically significant high specificity and positive predictive values in cases of postsurgical endophthalmitis, late-onset endophthalmitis associated with glaucoma procedures, postintravitreal injection and endophthalmitis associated with bacterial keratitis. Coagulase Negative Staphylococcus was the most common organism isolated from vitreous and aqueous samples.

Conclusions Even though the sensitivity and specificity of aqueous tap are low, our results show that in a few cases it identified important organisms, otherwise missed by vitreous sampling alone. Culture of vitreous sample remains the gold standard for isolation of pathogen in bacterial endophthalmitis, but aqueous samples should also be obtained as an adjunct for the diagnosis.

  • vitreous
  • infection
  • inflammation
  • anterior chamber
  • aqueous humour

Data availability statement

Data are available upon reasonable request.

Statistics from Altmetric.com

Data availability statement

Data are available upon reasonable request.

View Full Text

Footnotes

  • Contributors AFA designed the work, analysed the data, drafted and revised the work critically for important intellectual content and approved the final version to be published. SA-R designed the work, analysed the data, drafted and revised the work critically for important intellectual content and approved the final version to be published. IT designed the work, drafted and revised it critically for important intellectual content and approved the final version to be published. CW drafted and revised the work critically for important intellectual content and approved the final version to be published. NG-M drafted the work and revised it critically for important intellectual content. He approved the final version to be published. CP designed the work, analysed the data, drafted and revised the work critically for important intellectual content and approved the final version to be published. He agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Disclaimer The views expressed in the publication are those of the authors and not necessarily those of the Department of Health.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.