Increased Intracranial Pressure: Papilledema
Papilledema is the term reserved for a swollen optic disc caused by increased intracranial pressure. Papilledema is nearly always found in both eyes, although the swelling may be asymmetric.
The disc swelling is the result of a slow-down in axoplasmic flow from the retina to the lateral geniculate body. As a consequence, the axons swell. Vision does not fail unless axoplasmic flow stops altogether. That will happen if the intracranial pressure is severely elevated for many weeks.
What to do?
If you believe the patient has papilledema, you must infer increased intracranial pressure. Most observers consider increased intracranial pressure a medical emergency even though some conditions are chronic. Prudence dictates that the patient be referred promptly for ophthalmologic confirmation, as there are many "foolers."