Clinical Evaluation of Optic Nerve Head in Glaucoma

Glaucomatous optic neuropathy is characterized by changes in the intrapapillary and parapapillary region of the optic nerve head, including excavation of the optic nerve head and consequent defects in retinal sensitivity with visual field defects and other psychophysical alterations. Clinical evaluation of the optic nerve head has been shown to have a high specificity and good precision for glaucoma diagnosis and an experienced observer may in fact be better in distinguishing between normal and glaucomatous disks in comparison with the HRT or OCT. It is important to differentiate normal physiologic variations in the optic cup, the neural rim, and the peripapillary retina, developmental anomalies and nonglaucomatous optic atrophies from glaucomatous optic nerve head changes. This review attempts to elucidate the morphology and anatomy of the opic nerve head, and correlate the same to the pathophysiology of glaucomatous optic neuropathy.