A 60-year-old male judge with hypertension and diabetes describes a single episode of monocular transient visual loss OD. A dark curtain descended from superior to inferior OD, lasted 10 minutes and then spontaneously resolved. The patient was seen by an outside ophthalmologist and a diagnosis of “retinal migraine” was made. The next day the patient suffers two more episodes of similar visual loss and calls the ophthalmologist back and is given a referral for a two week appointment to neurology for “migraine”. That night the patient suffers a hemispheric stroke with hemiparesis and aphasia. A carotid study shows near occlusion of the right internal carotid artery.\nThe diagnosis of “retinal migraine” is one of exclusion. In elderly patients the diagnosis should be made with caution in the absence of headache history, prior attacks without residual or sequelae, and in patients who have vasculopathic risk factors. The International Headache Society (IHS) criteria for the diagnosis include: “≥ 2 attacks of “fully reversible” monocular visual loss with migraine headache”. The presumptive vasospasm mechanism for migraine headache and visual aura has fallen out of favor and spreading depression of cortical neuronal activity is a more plausible explanation for the visual symptoms in migraine. Unfortunately there is no diagnostic test for the migraine aura and a convincing history is required for the diagnosis. The role of the ophthalmologist is to exclude permanent visual loss after the event by performing formal visual field, documenting that there is no permanent residual loss, and ruling out alternative etiologies or eye markers for ischemic disease (e.g., central or branch retinal artery occlusion, Hollenhorst plaque). The most characteristic historical features for migraine are positive (e.g., scintillation or fortification scotoma) rather than negative (e.g., a black curtain) visual phenomenon; march and build up across the visual field in a nonvascular distribution, stereotyped quality with repeated events without permanent sequelae; and preferably the headache follows the aura after a few minutes duration. The most worrisome historical features for ischemia as the cause for amaurosis fugax include older aged, vasculopathic patient with first onset of an altitudinal (e.g., curtain over my vision) onset and disappearance, duration of minutes (1-10”), and seconds in onset. I would consider ordering a work up in transient monocular visual loss for patients with altitudinal history (e.g., curtain of visual loss), visible embolus, residual visual field defect, vasculopathic risk factors, and an ischemic time course. I would expedite the evaluation if the course was one of an increasing crescendo of events. On the other hand, I often defer work up for visual loss symptoms which have been present for years (e.g., hundreds of events with no residual loss) or have longer duration (e.g., 1-2 hours to days); are non-altitudinal events, the patient has no vasculopathic risk factors, or gives only a vague history of blurring. The clinician should also try to elicit a history suggestive of fluctuating rather than transient visual loss that might suggest the more common benign etiologies like ocular surface disorders or dry eyes. I will give these latter patients a pinhole to try during the events and if it alleviates the problem then it can be safely assumed to be ocular surface or refractive in nature. I also ask the patients to keep a diary of their events to establish some of the historical details above and I often give an empiric artificial tear trial.
A 30-year-old man presents with acute onset of unilateral optic disc edema with a macular star figure of exudate OD. The vision was 20/200 OD, there is right RAPD, and a cecocentral scotoma on visual field testing OD. There is mild vitreous cell OD. The ophthalmologist writes'“papilledema” on the chart and refers the patient to a neurologist for further testing. The neurologist orders a head MRI which is normal and performs a lumbar puncture that shows a normal opening pressure and cerebrospinal fluid analysis. The patient sees another ophthalmologist for a second opinion and the correct diagnosis of cat scratch neuroretinitis is made based upon a markedly elevated Bartonella henselae titer (IgG 1:1024).\nPapilledema for neuro-ophthalmologist represents a term that is best reserved for optic disc swelling due to elevated intracranial pressure. It is my recommendation that all other causes of optic disc swelling should be referred to by etiology (e.g., optic neuritis, or anterior ischemic optic neuropathy) or simply by describing the ophthalmoscopic finding of “optic disc edema” Clinicians should use the term “papilledema” carefully because it is potentially confusing to your colleagues in neurology, neurosurgery, and medicine if you misuse the term. This inappropriate charting could lead to inappropriate testing? (e.g., the MRI and lumbar puncture in this case). It also delays testing for the real culprit for the patient's optic disc edema and a macular star figure (i.e., infectious cat scratch neuroretinitis in this case). The misleading documentation could also lead to medicolegal implications of the missed diagnosis.\nIn general the clinician can use the clinical presentation to differentiate the three major forms of optic disc edema: papilledema, anterior ischemic optic neuropathy, and optic neuritis. Papilledema can occur at any age, is typically associated with relatively preserved central visual acuity (unless there is macular exudate, fluid, hemorrhage, or chronic or long standing papilledema), is bilateral (although markedly asymmetric or frankly unilateral cases do occur), and usually produces a big blind spot initially on visual field testing followed by nerve fiber layer loss over time. There might also be associated signs and symptoms of increased intracranial pressure (e.g., headache, nausea, vomiting, pulse synchronous tinnitus, or diplopia from a nonlocalizing sixth nerve palsy). In contrast to papilledema, optic neuritis typically affects younger patients, is often associated with decreased central acuity and dyschromatopsia, is typically unilateral (although bilateral cases can occur especially in children), and the visual field defect is usually a central scotoma (although any type of optic nerve related visual field loss may occur). Finally, in an older adult, anterior ischemic optic neuropathy is the most common unilateral cause for optic disc edema. The patient may have vasculopathic risk factors, an altitudinal visual field defect (but any optic nerve type of defect can occur), and again is usually unilateral. Thus the clinician should be wary of making the diagnosis of bilateral simultaneous optic disc edema related to either optic neuritis or non-artertic anterior ischemic optic neuropathy and probably should exclude papilledema in these clinical settings.\nThe evaluation of papilledema should include a check of the systemic blood pressure as malignant hypertension can mimic papilledema (i.e., hypertensive optic disc edema). Neuroimaging (preferably an MRI with contrast and an MR venogram to exclude venous sinus thrombosis) should be considered as the initial study in papilledema. If the neuroimaging study is normal then a lumbar puncture with an opening pressure and cerebrospinal fluid analysis should be performed. If the intracranial pressure is elevated, the neuorimaging is normal, and the CSF analysis is normal then the diagnosis of idiopathic intracranial hypertension can be confirmed but should be considered a diagnosis of exclusion. Although a CT scan might be the initial emergent neuroimaging study performed, there are many etiologies for increased ICP that may be missed on CT scan especially a noncontrast study in the emergency room. These intracranial etiologies include cerebral venous sinus occlusion, arteriovenous or dural malformation, infiltrative neoplasm or disorders that produce meningeal enhancement (e.g., inflammatory, infectious, infiltrative, or neoplastic etiologies).\nAlthough routine, typical, and medication responsive papilledema from idiopathic intracranial hypertension might be managed by a general ophthalmologist, a referral to neuro-ophthalmology might still be necessary if the patient fails maximum medical therapy or presents with acute, severe visual loss. These patients might require surgical intervention (e.g., shunting procedure or optic nerve sheath fenestration) to prevent irreversible papilledema related visual loss. In addition, the diagnosis should be made with caution in the following atypical circumstances: the patient is thin rather than obese, elderly or a child rather than a young adult, and male rather than female. Consultation is also recommended for patients with progressive visual loss despite treatment, signs or symptoms not due to increased intracranial pressure, or any inflammatory intraocular signs that might suggest an inflammatory rather than idiopathic etiology.