Advances in the assessment of optic disc changes in early glaucoma

Looking for early glaucomatous changes in the morphology of the optic disc and retinal nerve fiber layer, ocular hypertensive subjects should be checked to determine 1) whether the neuroretinal rim has its characteristic physiologic form with its largest parts in the inferior and superior disc regions and its smaller part in the temporal disc sector; 2) whether zone beta of the parapapillary chorioretinal atrophy is present or whether zone alpha is abnormally large; 3) whether the visibility of the retinal nerve fiber layer is diffusely reduced; and 4) whether localized defects of the retinal nerve fiber layer can be detected. Usually not occurring in normal eyes, an optic disc hemorrhage also indicates abnormality. These variables can be evaluated in every routine ophthalmoscopic examination, or by applying sophisticated techniques such as the scanning laser tomography and measurement of the height and contour of the parapapillary retinal nerve fiber layer.