other causes of optic neuropathy or visual field loss. Unless the practitioner is comfortable with performing a full neuro-ophthalmological evaluation and ordering appropriate investigations on this basis, he/she should request a consultation from a neuro-ophthalmologist. This ensures that neuro-imaging studies will be properly directed by the physical findings of the entire visual system.

Summary for the Clinician

››Cupping is a key feature of glaucomatous optic neuropathy but can also be found in other optic neuropathies.

››Dilated disc examination is required to provide an adequate binocular view for stereoscopic assessment of cup depth and distribution of pallor, and to facilitate slit-lamp measurement of vertical disc diameter and cup-to-disc ratio.

››Measure overall disc size (vertical disc diameter) to provide a context for the cup size - large discs may have physiologically large cups while small discs may have small cups which carry the possibility of masking changes we more classically associate with glaucomatous damage.

››Physiologically large cups may be normal in large discs but this can only be diagnosed with certainty in retrospect, when there has been no glaucomatous change over a period of time.

››Monitoring for change over a time period may ultimately be the only way to distinguish between glaucomatous pathology vs. individual anatomy in patients with large discs.

››Although the base of the cup in glaucomatous optic neuropathy is pale, giving the impression of optic disc pallor, the remaining neuroretinal rim maintains its yellow-pink color. In the absence of other pathology, a glaucoma disc should not be described as “pale.”

››Pallor of the neuroretinal rim should prompt the clinician to consider nonglaucomatous causes of the disc changes and field loss.

››If visual field loss does not correlate with glaucomatous features on disc examination, suspect another etiology and request assistance from an appropriate specialist.

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