A 55-year-old man with hypertension and diabetes presents with new awareness of blurred vision OD for two months. The visual acuity was 20/25 OD and 20/20 OS. Goldmann perimetry demonstrated an inferior altitudinal visual field loss OD. The pupil examination showed a relative afferent pupillary defect (RAPD) OD. Ophthalmoscopy showed a pale optic nerve OD. The eye exam was normal OS. A diagnosis of “optic atrophy” OD was made and the patient was instructed to return in 3 months for a repeat visual field. The patient returns in 3 months and the vision is now counting fingers OD. Magnetic resonance imaging of the head and orbit showed optic nerve sheath enhancement OD consistent with an optic nerve sheath meningioma.\nOptic atrophy is not a diagnosis. The clinician should document a cause for the optic atrophy and if no etiology is established a neuroimaging study and other evaluation should be performed. In a 55-year-old vasculopathic male the most likely etiology for a unilateral optic neuropathy with optic atrophy is non-arteritic anterior ischemic optic neuropathy (NA-AION). The “anterior” in NA-AION refers to optic disc edema and the absence of documented disc edema phase should prompt consideration for evaluation for alternative etiologies. In this case the patient experienced acute awareness of his visual loss OD rather than acute onset and the disc edema phase was not seen. Although serial visual field and follow up for a presumptive diagnosis of optic atrophy due to NA-AION is reasonable the clinical plan should be well documented in the chart, the patient should be informed of the possibility for a compressive or other etiology, and imaging and other evaluation should be pursued if the patient has progressive signs or symptoms (as in this case).\nLee et al. previously reported on the diagnostic yield for the evaluation of isolated and unexplained optic atrophy. This study was a retrospective review of all charts with the diagnosis of optic atrophy. Included patients were adults with isolated, but unexplained, optic atrophy and patients were excluded if they were children, had incomplete or inadequate documentation of the findings, had non-neurologically isolated optic atrophy (e.g., other localizing findings), or had a history (e.g., prior neuroimaging study showed a compressive lesion, prior ischemic optic neuropathy) or examination (e.g., central retinal artery occlusion) evidence for an etiology for the optic atrophy. A total of 1110 charts with the diagnosis of optic atrophy were reviewed from the two participating institutions (368 from the University of Cincinnati and 742 from the University of Iowa). Of these 1110 charts, 91 (8%) with isolated unexplained optic atrophy were included, and 1019 charts (92%) were excluded. Of the 91 cases included 18 (20%) had an underlying compressive lesion causing optic atrophy and 73 (80%) cases had no etiology for the optic atrophy on neuroimaging. Of the 18 patients with abnormal neuroimaging studies (e.g., meningioma, pituitary adenoma, or craniopharyngioma) 11 had bilateral and 7 had unilateral optic atrophy. Five of the 18 patients had progressive visual loss, 3 had hemianopic visual field loss, and 11 were younger than 50 years old. This study demonstrates that the risk of missing a compressive lesion in unexplained optic atrophy is high (20%) and that clinicians should not make the diagnosis of optic atrophy alone without an underlying proven or postulated mechanism.
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.