[Optic papilla parameters in healthy subjects--quantified with the optic nerve head analyzer]

The cup-disk ratio (CDR), the size of the neuroretinal rim area as well as the other disk parameters investigated with the Optic Nerve Head Analyzer (ONHA) were measured in double examinations of 32 healthy eyes in 32 patients. Thus, "normal" values were determined for the various disk parameters. A new method is presented for calculating one average pallor value for the disk. The mean value for disk pallor in healthy eyes is determined. Examination of the CDR in the quadrants of the disk reveals significant differences. According to the results of a multi-regressional analysis of the various disk parameters, the size of the neuroretinal rim area in healthy eyes is influenced by the size of the disk, the disk volume and the elevation volume. The correlation between the size of the neuroretinal rim area and the size of the disk reveals a significant interdependence: a larger disk also has a greater neuroretinal rim area as compared to a smaller disk. This means that sizes of neuroretinal rim areas of different disk should only be compared when the disks are the same size. Relative values, such as the CDR or the ratio between the size of the neuroretinal rim area and disk size (rim area/disk area), are therefore better suited for comparison.