A perimetric nerve fiber bundle map

The so-called 'nerve fiber bundle defects' in the visual field are considered as being the functional equivalent of retinal nerve fiber bundle damage. This study examines the course and the position of scotoma borders in 159 visual fields with complete nerve fiber bundle defects using high resolution test point patterns. The scotoma border lines were averaged geometrically. The result is presented in the form of mean vectors. This functional map of nerve fiber lines shows a close correspondence to the anatomical course of the retinal nerve fibers. To make the result suitable for topographical analysis of visual fields, 21 areas ('Perimetric Nerve Fiber Bundles') are defined. Certain arbitrary assumptions were necessary because data were to scanty in some nasal regions. Also, the lines had to be fitted into a rectangular grid to be transferable to standard perimetric patterns. Topographical analysis on the basis of these areas may be useful for the evaluation of visual fields, particularly those of glaucoma.