Understanding the dynamic provoked circulatory response of the papilla.

The author explains the difficulties of a topographical quantification of papillary changes. On the one hand this is due to the unprecise definition of the papilla's boundaries, on the other hand these boundaries might themselves fluctuate. Afterwards a description of the dynamic provoked circulatory response follows. This is an examination which tests the change of redness of the rim when the intraocular pressure is artificially risen. Two properties of the vascular system of the papilla are checked with it. When looking at the 'latency time', the time which elapses between beginning of the provocation and beginning of pallor increase, the vascular resistance is controlled. When measuring a decrease of pallor while increasing the intraocular pressure autoregulation of the papillary capillaries are tested. The dynamic provoked circulatory response is the only clinically available test of the papilla's vascular system.