[The neuro-retinal rim region in early glaucoma].

The true neuro-retinal rim area of the optic disc was obtained by calculating the magnification using axial length, refraction and corneal curvature. Patients with very early chronic open angle glaucoma and normals were compared. The neuro-retinal rim area separated these two populations better than the standard cup/disc ratios. The size of the optic nerve did not appear to change with age. The implications for clinical practice are outlined.