Autoregulation of choroidal blood flow in the rabbit.

摘要: Previous studies show that choroidal blood flow is not autoregulated when intraocular pressure (IOP) increased to raise venous and lower the perfusion gradient. However, autoregulatory response changes in mean arterial (MAP) unclear. In current study, gradient (MAP-IOP) was altered by (1) decreasing MAP while IOP held at 5, 15, 25 mmHg, (2) increasing prevailing anesthetized rabbits (n = 8). An occluder on thoracic vena cava used vary MAP; this monitored through an ear artery catheter. Two catheters were inserted vitreous monitor control IOP. Choroidal measured laser Doppler flowmetry using a slender stainless-steel probe positioned next retinal surface. The efficacy of autoregulation depended When constant 5 did fall until less than 40 mmHg. pressure-flow relationship became progressively more linear (ie, decreased) 15 varied constant, IOPs greater 20-25 independent Simultations myogenic mathematic model choroid gave results similar experimental observations. It concluded mechanism may be responsible for rabbit.