The role of clinical examination of the optic nerve head in glaucoma today

Purpose of review The study was undertaken to assess the current importance of clinical examination of the optic nerve head (ONH) in glaucoma management. Recent findings ONH changes in glaucoma are easily assessed with good specificity on examination, whereas imaging has not been able to identify pallor of the neuroretinal rim (NRR), disc hemorrhages, or vascular signs of acquired cupping. Glaucomatous neuropathy in primary open angle glaucoma (POAG) has extensive databases on imaging machines, however, other glaucomas such as primary angle closure glaucoma (PACG), juvenile open angle glaucoma (JOAG), congenital, and secondary glaucomas have been reported to have a significantly different ONH morphology. Clinical evaluation with knowledge of the underlying cause of glaucoma allows easy diagnosis of any abnormality, whereas the absence of an imaging database in such eyes makes diagnosis difficult on optical coherence tomography (OCT) and so forth. In eyes with congenital anomalies and dysplastic discs, clinical examination and history provide better identification of glaucomatous damage. Staging of glaucoma on ONH examination when perimetry is unreliable provides a means of determining the amount of damage and appropriate reduction of intraocular pressure (IOP). Clinical examination of the ONH is very relevant for screening, diagnosis, staging, and management of all glaucomas, and is irreplaceable in detecting nonglaucomatous causes of ONH cupping and visual field defects similar to those in glaucoma.