Changes in the Optic-Nerve Head over Time in Normal-Tension Glaucoma

Recently, various kinds of computer-assisted image-analysis systems and instruments have been developed in the field of glaucoma diagnosis [1-3]. It has been stressed that one of the advantages of using computerized image-analysis methods is the ability to detect changes over time in the optic-nerve head or nerve-fiber layer [4]. This is because computerized techniques are not influenced by bias, unlike clinicians’ subjective evaluations based on ophthalmoscopic findings. However, to what extent such techniques can detect differences in the configuration of the optic-nerve head over time is not yet fully understood. The purpose of this study was to evaluate changes in the optic-nerve head over time by means of scanning laser tomography in patients with normal-tension glaucoma.