This project will use a rat model of peri-operative ischemic optic neuropathy (ION) to examine mechanisms of axonal injury and to provide important new data to understand and prevent an important clinical problem that results in visual loss. Outcome after ischemia will be primarily studied using functional criteria (evoked response to light flashes, and antegrade transmission of tracers through the visual pathway measured using magnetic resonance imaging), by the degree of edema or demyelination in the optic nerve (by MRI), and by molecular markers of cell death in the retinal ganglion cells. By manipulating systemic blood pressure, hemoglobin levels, and head position in rats placed for prolonged time periods in the prone position, we will examine the mechanisms of the devastating injury and begin to evaluate preventive strategies.
Ischemic optic neuropathy is a devastating injury that results in visual loss. By gaining a better understanding of the mechanisms of this injury, we will diminish suffering and the cost of care for these patients. In addition, we will gain insights into the mechanisms of axonal loss after ischemia. Axonal loss occurs in other conditions such as stroke, and therefore the implications of our findings could be more widely applied.