[Can the extent of glaucoma damage be assessed by measuring the asymmetry of the peripapillary height profile between the upper and lower retinal half? A clinical study with the Heidelberg Retina Tomograph].

BACKGROUND

Peripapillary height measurements are possible using 2 different reference planes of the Heidelberg-Retina-Tomograph. It is not tested yet, whether the extent of glaucoma damage should be better quantified using reference plane 1 or 2.

PATIENTS AND METHODS

In 32 eyes of 32 glaucoma patients with a defined up-down asymmetry of visual field loss is tested I.) if there is a significant correlation between peripapillary height and visual field loss comparing reference plane 1 and 2. II.) if there is a conformable up-down asymmetry of the peripapillary height using a new "retinal-asymmetry-difference" (RAD). III.) if conformity between peripapillary height and visual field loss depends on the distance from the disc margin.

RESULTS

1.) For an advanced visual field loss there was a significant correlation between visual field loss and peripapillary height using reference plane 1. II.) In eyes with a big up-down asymmetry of visual field loss there was a bigger conformity between the up-down asymmetry of visual field loss and the up-down asymmetry of peripapillary height (11 of 12 eyes), as for a small up-down asymmetry (12 of 20 eyes). III.) Conformity decreases with the distance from the disc margin.

CONCLUSIONS

Peripapillary height should be examined using measurement circles near the disc margin. Because of its independence on the age and on different reference planes additional calculation of an up-down "retinal-asymmetry-difference" (RAD) seems to be useful. Using this up-down "retinal-asymmetry-difference" (RAD) a big up-down asymmetry of visual field loss, equivalent to an advanced glaucomatous disease, is quantified with high sensitivity.