1. A method for mapping a plurality of summary values of a retinal parameter to a measurement grid comprising a plurality of neighborhoods, comprising the steps of: displaying a fundus image; rendering a two-dimensional composite image from a three-dimensional volume dataset; registering the two-dimensional composite image to the fundus image; displaying the measurement grid on the two-dimensional composite image; moving, in response to user input, the measurement grid to a region of interest; and calculating at least one of said plurality of summary values in each of said plurality of neighborhoods.