title: Damping of intraocular pressure fluctuations.
abstract: BACKGROUND
  There is increasing evidence that relatively rapid spikes in intraocular pressure may contribute to axonal damage in glaucoma. The present study seeks to quantify the ability of a compressible damping element (a simple air bubble) to reduce intraocular pressure fluctuations induced by a known change in intraocular fluid volume.
  
  
  METHODS
  A mathematical model describing the damping of intraocular pressure increases for a given infusion volume was developed and compared with experimental data obtained from isolated pig eyes. A damping element (100 µL to 2 mL of air) was added to the system, and the effect on the induced intraocular pressure change for a given infusion volume was assessed.
  
  
  RESULTS
  The introduction of the damping element reduced the intraocular pressure change in a volume-dependent manner consistent with the mathematical modelling. The maximum bubble size tested (2 mL) dampened the intraocular pressure change by an average of 63.5 ± 8.7% at a baseline pressure close to 20 mmHg. Close agreement was seen between the mathematical model and the experimental data.
  
  
  CONCLUSIONS
  Mathematical modelling and experiments in isolated pig eyes demonstrated that the addition of a damping element in the form of a compressible air bubble is capable of significantly reducing induced intraocular pressure spikes.
authors.affiliation: Centre for Ophthalmology and Visual Science, and the ARC Centre of Excellence in Vision Science, The University of Western Australia, Perth, Western Australia, Australia. cringle@cyllene.uwa.edu.au
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Cringle
authors.forename: Dao-Yi
authors.initials: DY
authors.lastname: Yu
mesh_terms: D000388:Air; D000818:Animals; D000867:Anterior Chamber / Q000502:physiology; D002404:Catheterization; D058450:Endotamponade / Q000379:methods*; D007429:Intraocular Pressure / Q000502:physiology*; D008962:Models, Theoretical; D011312:Pressure; D013552:Swine; D014065:Tonometry, Ocular