title: Characterization of the pupil light reflex, electroretinogram and tonometric parameters in healthy mouse eyes.
abstract: OBJECTIVE
  To characterize the pupil light reflex (PLR), electroretinographic (ERG) and tonometric parameters which might be of importance for the in vivo characterization of mouse models of chronic ocular hypertension.
  
  
  METHODS
  C57/BL6 mice were used for experiments. The PLR was evaluated with a computerized pupillometer (n = 14), ERGs were recorded simultaneously from both eyes (n = 23) and IOP was measured with a modified Goldmann tonometer (n = 23).
  
  
  RESULTS
  The analysis of the PLR parameters confirmed the consensual PLR did not have significantly different amplitude (p > 0.1) and latency time (p > 0.1) compared to the direct PLR. However, PLR velocity (p = 0.004) was significantly smaller in the consensual PLR. Electroretinography revealed a-wave amplitude of 168.3 +/- 9.6 microV with latency of 27.5 +/- 0.6 ms and b-wave 403 +/- 28.8 microV with latency of 22.7 +/- 0.6 ms. The flicker ERG recording revealed amplitudes of 20.6 +/- 2.4 microV. Tonometry experiments revealed that modified Goldmann tonometer measurements correlated well with invasive manometry (r(2) = 0.89). The mean IOP of the mouse was 15.3 +/- 0.6 mmHg.
  
  
  CONCLUSIONS
  Consensual PLR in mice is relatively slower than the direct PLR, but retains the same degree of constriction comparing to the direct PLR. A modified Goldmann tonometer seems to be a reliable non-invasive tool for IOP measurements in mice.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA. sgrozdan@iastate.edu
authors.forename: Sinisa
authors.initials: S
authors.lastname: Grozdanic
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Betts
authors.forename: Rachell A
authors.initials: RA
authors.lastname: Allbaugh
authors.forename: Donald S
authors.initials: DS
authors.lastname: Sakaguchi
authors.forename: Young H
authors.initials: YH
authors.lastname: Kwon
authors.forename: Randy H
authors.initials: RH
authors.lastname: Kardon
authors.forename: Ioana M
authors.initials: IM
authors.lastname: Sonea
mesh_terms: D000818:Animals; D004596:Electroretinography; D007429:Intraocular Pressure; D051379:Mice; D008810:Mice, Inbred C57BL; D009799:Ocular Physiological Phenomena; D011930:Reaction Time; D012016:Reference Values; D012025:Reflex, Pupillary; D014065:Tonometry, Ocular