Neuro-ophthalmology of orbital disease.

In this chapter the presentation and management of common orbital diseases are discussed. An accurate clinical history and assessment are essential, with computed tomography being the imaging of choice. Magnetic resonance imaging provides detail of intrinsic optic nerve disease and orbital apical or intracranial pathology, and ultrasonography is valuable in assessing anterior orbital masses, in particular vascular lesions. Inflammatory lesions require a tissue biopsy before immunosuppression is instituted. Exceptions to this principle are scleritis, myositis, thyroid eye disease, and characteristic orbital apex syndrome, in which delay in immune suppression may jeopardize visual outcome. The term "orbital pseudotumor" is now obsolete. The management of active thyroid eye disease includes immunosuppression and low-dose orbital radiotherapy. Urgent orbital decompression is indicated in the presence of nonresponsive optic neuropathy, and inactive disease is managed by decompression for exophthalmos, and correction of muscle imbalance and lid retraction. Subacute lacrimal gland inflammation, unresponsive to a few weeks of nonsteroidal treatment, may be due to underlying carcinoma and a specialist opinion should be sought without delay. Pleomorphic adenoma, with typical features on imaging, should always be excised intact to avoid subsequent pervasive malignant disease.