[Measurement of blood velocity of rabbit iris by laser speckle flowgraphy].

We developed laser speckle flowgraphy which displays the relative velocity of blood microcirculation as a color map in two dimensions. We applied this method to the iris in 10 eyes of 5 normal white rabbits under general anesthesia. The coefficient of variation was small and averaged 5.6. There was no significant difference in the values measured on 3 consecutive days. The blood velocity in the iris increased significantly during experimental ocular hypotony and decreased during ocular hypertension and 2 hours after instillation of timolol (p less than 0.05). These findings indicate that the present method is of value in assessing the relative velocity of iris microcirculation in vivo and that topical instillation of timolol induces decrease of blood flow in the iris and, possibly, in the ciliary body.