A comparison of the mean defect and mean deviation indices within the central 28 degrees of the glaucomatous visual field.

The mean defect index of Flammer and the mean deviation index of Heijl have been compared based on a study of 169 glaucomatous visual fields. It is shown that in the cases studied the differences between the two indices are negligible for Octopus G1 program results and that they may thus be used interchangeably.