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Abstract #5277 Published in IGR 1-2
Effet d'une diminution de la pression de perfusion oculaire sur le flux sanguin dans l'iris mesuré par fluxmétrie laser Doppler(Effect of a decreased ocular perfusion pressure on iris blood flow measured with laser Doppler flowmetry)
Chamot SR; Movaffaghy A; Petrig BL; Riva CEKlinische Monatsblätter für Augenheilkunde 1999; 214: 302-304
PURPOSE: To determine whether iris blood flow (IBF) is regulated in response to an acute decrease in mean ocular perfusion pressure (PPm=MOAP-IOP, MOAP=mean ophthalmic arterial pressure) induced by increasing the intraocular pressure (IOP). METHODS: Iris blood flow was measured using a slit lamp incorporating a laser Doppler flowmetry (LDF) module. The study was conducted on 12 normal volunteers (14 to 59 years old). IOP was raised using a scleral suction cup. In Exp. #1, the suction pressure was successively raised in steps of 50 to 100 mmHg, each lasting about 10 sec, until IOP reached the MOAP level. In Exp. #2, the suction was raised to 200 mmHg in 4 successive steps of 2 min duration. RESULTS: In Exp. #1, no significant change of IBF was observed for small decreased of PPm (<23%); greater decreases of PPm resulted in a linear IBF decrease (p<0.01). In Exp. #2, such an IBF versus PPm decrease was also observed (p<0.001). Immediately after release of suction, a significant, transient IBF increase of 79% above baseline level was observed. CONCLUSION: These results suggest that some IBF regulation occurs for small PPm decreases (<23%); no IBF compensatory mechanism appears to operate for further decreases of PPm (>23%). (French)
S.R. Chamot, Institut de Recherche en Ophtalmologie, Av. Grand-Champsec 64, CH-1950 Sion 4; Switzerland
Classification:
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)
