|OPTIC DISC EDEMA & PAPILLEDEMA
In general, you may observe an enlarged physiologic blind spot in any form of disc edema which displaces the peripapillary photoreceptors. Arcuate scotomas are also common when the inferior and superior poles of the disc are compromised. Altitudinal defects may be seen in ischemic and demyelinating neuropathies; central and cecocentral scotomas are common in primary optic nerve inflammations and infections. If disc swelling is unilateral and vision is poor, expect to find a relative afferent pupillary defect in the involved eye.
True bilateral papilledema will not present with an afferent pupillary defect. The earliest signs of disc edema include striations within the nerve fiber layer in conjunction with blurring of the superior and inferior margins of the neural rim tissue. The disc itself will, in time, protrude from the retinal surface. In cases of inflammation or papilledema, it may display hyperemia and capillary dilation. In ischemic optic neuropathy, the disc is swollen and elevated, but characteristically pale. In more severe presentations of optic disc edema, the retinal venules become engorged and tortuous, hemorrhages and/or cotton wool spots form in the peripapillary area, and you'll see circumferential retinal microfolds (Paton's lines) in the region surrounding the disc. Chronic disc edema may ultimately result in atrophy of the nerve head, with associated pallor and gliosis of the rim tissue.
If the signs indicate an optic neuropathy such as papillitis or anterior ischemic optic neuropathy, management is aimed at treating the underlying disorder. Often, this involves systemic steroids, particularly when the etiology is inflammatory. You must obtain a CT or MRI scan of the brain within 24 hours of any tentative diagnosis of papilledema (i.e., when you suspect that increased intracranial pressure is the cause of the disc edema). These tests may help to identify an intracranial mass lesion, such as tumor, hemorrhage or abscess; in addition, the appearance of the cerebral ventricles may indicate hydrocephalus or pseudotumor cerebri. In the absence of positive radiographic studies, lumbar puncture may yield information regarding meningitis, encephalitis, or spinal cord tumors. Neurological consultation and co-management is obligatory in all cases of intracranial hypertension.
The treatment of papilledema and its underlying causes may be medical or surgical, depending upon the disorder. Neuro-ophthalmologists have attempted surgical therapy of the optic nerve using optic nerve sheath decompression to alleviate fluid retention within the surrounding meninges by creating a small fenestration site within the intraorbital portion of the nerve. While this procedure has yielded some positive results, it is extremely complex work and may fail in up to one-third of all cases.
Other reports in this section
Eyelids & Eyelashes | Conjunctiva & Sclera | Cornea
Uvea | Vitreous & Retina | Optic Nerve & Brain | Oculosystemic Disease
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