PMID- 12356830
OWN - NLM
STAT- MEDLINE
DCOM- 20021108
LR  - 20220409
IS  - 0146-0404 (Print)
IS  - 0146-0404 (Linking)
VI  - 43
IP  - 10
DP  - 2002 Oct
TI  - Optic disc movement with variations in intraocular and cerebrospinal fluid 
      pressure.
PG  - 3236-42
AB  - PURPOSE: To determine the effect of intraocular pressure (IOP) and cerebrospinal 
      fluid pressure (CSFP) on optic disc movement and lamina cribrosa displacement 
      using confocal scanning laser tomography (CSLT). METHODS: The anterior chamber 
      and lateral ventricles were cannulated in mixed-breed dogs (n = 8) to allow 
      modulation and control of IOP and CSFP, respectively. Optic disc topography was 
      determined after baseline (set at IOP 15 mm Hg and CSFP of 0 mm Hg) and with each 
      step-wise increase in IOP (steps of 3-5 mm Hg up to an average of 32 mm Hg) with 
      CSFP fixed at 0 mm Hg. After the pressure returned to baseline, images were 
      obtained after each step-wise increase in CSFP (steps of 2 to 4 mm Hg up to an 
      average of 12 mm Hg) with IOP fixed at 15 mm Hg. Data were analyzed by a new 
      probabilistic method for CSLT and global parameters generated by the instrument 
      software. The global parameter changes from baseline were analyzed as a function 
      of the translaminar pressure difference (IOP minus CSFP). RESULTS: Elevation in 
      IOP resulted in significant posterior displacement of the disc surface, whereas 
      elevation in CSFP resulted in significant anterior displacement. For a given 
      degree of pressure change, an increase in CSFP resulted in larger changes than a 
      corresponding increase in IOP. The deepest 5% of locations within the disc 
      surface were displaced nonlinearly (with an inverse exponential function, r = 
      0.92) as a function of the difference in translaminar pressure. Most displacement 
      occurred at low translaminar pressure differences, with little extra movement at 
      differences higher than 15 mm Hg. The change in the volume subtended by the 
      anterior lamina cribrosa showed a nonlinear relationship similar to the 
      translaminar pressure difference (r = 0.98), with negligible volume change at 
      high difference in pressures. CONCLUSIONS: Most optic disc movement occurs with 
      pressure changes in the low range of translaminar pressure differences. This is 
      consistent with the mechanical properties of collagen.
FAU - Morgan, William H
AU  - Morgan WH
AD  - Lions Eye Institute, University of Western Australia, Perth, Australia. 
      whmorgan@cyllen.uwa.edu.au
FAU - Chauhan, Balwantray C
AU  - Chauhan BC
FAU - Yu, Dao-Yi
AU  - Yu DY
FAU - Cringle, Stephen J
AU  - Cringle SJ
FAU - Alder, Valerie A
AU  - Alder VA
FAU - House, Phillip H
AU  - House PH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Invest Ophthalmol Vis Sci
JT  - Investigative ophthalmology & visual science
JID - 7703701
SB  - IM
MH  - Animals
MH  - Cerebrospinal Fluid Pressure/*physiology
MH  - Dogs
MH  - Intraocular Pressure/*physiology
MH  - Models, Biological
MH  - Motion
MH  - Optic Disk/*physiology
MH  - Probability
EDAT- 2002/10/03 04:00
MHDA- 2002/11/26 04:00
CRDT- 2002/10/03 04:00
PHST- 2002/10/03 04:00 [pubmed]
PHST- 2002/11/26 04:00 [medline]
PHST- 2002/10/03 04:00 [entrez]
PST - ppublish
SO  - Invest Ophthalmol Vis Sci. 2002 Oct;43(10):3236-42.