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.
A 65-year-old woman with hypertension and diabetes presents with new awareness of blurred vision OD for two days. The visual acuity was 20/40 OD and 20/20 OS. No visual field is performed. The pupil examination showed a relative afferent pupillary defect (RAPD) OD. Ophthalmoscopy showed a normal optic nerve OD. The remainder of the eye exam was normal OS. A diagnosis of “posterior ischemic optic neuropathy” (PION) is made and the patient is instructed to return for a “next available” visual field test. The patient returns two months later and reports that “his vision is worse”. The vision is now 20/400 OD and 20/25 OS. There is a right RAPD. The Goldmann visual field showed a bitemporal hemianopic visual field loss with a superimposed central loss OD. There is now optic atrophy OD. A cranial MRI showed a pituitary adenoma compressing the optic nerve OD. A new eye doctor sees the patient and tells her that “If only you'd come to me sooner you would not be blind.”\nThe diagnosis of posterior ischemic optic neuropathy (PION) is one of exclusion. PION does occur and can be classified as arteritic (i.e., related to giant cell arteritis) or non-arteritic. The non-arteritic form is generally seen in the setting of perioperative or post-operative ischemic optic neuropathy after spine or cardiovascular surgery. Post-operative PION however has been seen after multiple surgical procedures.\nSadda et al. reported a retrospective chart review of 72 patients (98 eyes) with a clinical diagnosis of PION: perioperative (28 patients), arteritic (6 patients), and nonarteritic systemic vascular disease (38 patients). Among eyes with nonarteritic PION, 34% experienced improvement in vision, 28% remained stable, and 38% worsened.\nIt is my opinion that before the diagnosis of PION can be made two conditions must be excluded. First giant cell arteritis and second a compressive lesion producing a retrobulbar optic neuropathy. The key feature differentiating AION from PION is the presence of optic disc edema in the acute setting. Retrobulbar optic neuritis is typically a disorder of young patients and most commonly associated with multiple sclerosis. Retrobulbar optic neuritis however is rare in the elderly and the diagnosis should not be made without an imaging study. Compressive lesions can mimic an acute onset as seen in ischemic disease. In addition, corticosteroids a common treatment of retrobulbar optic neuritis can be disastrous in a patient harboring a fungal orbital apex lesion producing the retrobulbar optic neuropathy. Thus the diagnosis of retrobulbar “optic neuritis” should be made with extreme caution in the elderly. I generally recommend that a fluorescein angiogram be considered in elderly patients with suspected PION. The finding of choroidal perfusion deficit in the setting of PION is strongly suggestive of giant cell arteritis. Corticosteroids might be useful empirically for both arteritic and nonarteritic PION but an imaging study as mentioned above might be advisable prior to starting treatment.\nI would accept the diagnosis of PION of the clinical findings are consistent with an optic neuropathy (i.e., visual loss, RAPD, optic neuropathy related visual field), there is a clear etiology (i.e., post-surgical PION or giant cell arteritis), and optic atrophy develops over time. If there is no clear etiology for the PION, then a neuroimaging study is recommended (preferably cranial MRI with contrast and orbital fat suppressed views).