[Glaucoma diagnosis with the GDx and measurement of nerve fibre thickness (RTA)].

Damage of retinal nerve fibres is an early sign of glaucoma.Therefore, a quantitative determination of nerve fibres would be an ideal technique for early glaucoma diagnosis. This can be realized by the GDx which uses nerve fibre polarimetry to measure the thickness of the parapapillary nerve fibre layer.A single GDx measurement in a glaucoma patient may be an important adjunct to the clinical findings.However, at present the method is not suitable for general screening. Presumably the most important application of the device is longitudinal monitoring. In contrast to the GDx,RTA determines the thickness of the whole retina, not specifically the nerve fibre layer. This might be a reason why the discrimination between normal subjects and glaucoma patients is somewhat more difficult than with the GDx.Again, longitudinal monitoring should be the most common application of the RTA in glaucoma patients. Besides glaucoma,RTA also allows examination of macular pathologies.RTA is a promising new technique which so far is not as frequently used as the GDx or the HRT.