Albumin in tears

  • Gunilla Runstrom

Student thesis: Doctoral ThesisDoctor of Philosophy

Abstract

Albumin is not endogenous to the tear film and is present as a product of plasma leakage. It is
used as a diagnostic marker of ocular insult and inflammation. Tear albumin is, however, poorly
understood, with large variations in reported concentrations between studies. There is also no
authoritative information on whether its presence in tears is responsive or part of an adaptive
reaction.The presented research aimed to resolve the disparities in published tear albumin
concentrations and investigate the role of albumin in the tear film. Collation and evaluation of
the available literature identified collection method, stimulus, assay technique, and disease state
as factors able to influence quoted tear albumin to different extents. Difference in sampling
technique exhibited the largest variations in mean tear albumin concentrations. Review of the
literature also highlighted that little systematic investigations of the daily cycle of tear albumin
levels, and subject-to-subject-variation, had been carried out. In order to remedy this shortcoming, variations in tear albumin concentration were investigated in 13 subjects throughout the waking day. Results identified a time period where albumin levels are relatively stable (2-6 hours post-waking). This was designated a suitable baseline for the determinations of tear albumin concentrations and subject-to-subject comparisons. Significantly, a previously
unrecognised progressive increase in albumin concentration during the latter part of the day was also identified in the population. This increase suggests that albumin may play a more active and dynamic role in the ocular environment than is commonly perceived. To facilitate the collection of additional tear albumin data, tear sampling and point-of-care analysis in contact
lens clinics were investigated. Two instruments were evaluated and were found to be suitable for the analysis of tear albumin in commercial institutions. Collectively, the described research has provided new insight into tear albumin and a strong
foundation for further studies.
Date of Award9 Jun 2013
LanguageEnglish
SupervisorBrian Tighe (Supervisor) & Paul Topham (Supervisor)

Keywords

  • tear sampling
  • point-of-care analysis
  • diurnal
  • vascular permeability
  • biomarker

Cite this

Albumin in tears
Runstrom, G. (Author). 9 Jun 2013

Student thesis: Doctoral ThesisDoctor of Philosophy