Pseudotumor cerebri syndrome (PTC, also referred to as idiopathic intracranial hypertension [IIH]) is classically taught as presenting in young, overweight women of childbearing age, with a history of headaches and findings of bilateral optic nerve swelling, associated with an elevated intracranial pressure. However, as with every "textbook" definition of a disease, there are atypical cases (children, men, thin people, older people), and so I am often confronted with some interesting diagnostic challenges when I am referred a patient that does not fit the typical picture of PTC who has bilateral optic nerve swelling.
Optociliary shunt vessels (retinochoroidal shunts), are normal congenital collaterals between the retinal and choroidal venous circulation. In conditions that cause chronic central retinal vein obstruction, venous outflow becomes redirected to the choroidal venous circulation, resulting in dilation of these collateral vessels.
Neuro-ophthalmology tends to have some of the more challenging questions, depending on your level of knowledge or comfort with these topics. One of the important things to recognize and evaluate is the swollen optic nerve.
There are relatively few causes for tunnel visual fields (or “gun barrel” visual fields), which is a relatively common finding in neuro-ophthalmology. There are 8 major categories of tunnel visual fields, which can be determined systematically through careful history and examination. This differential diagnosis is adopted from Duane’s Clinical Ophthalmology.