Orbit

Alex V. Levin

Thomas W. Wilson

Dan DeAngelis

Robert Pashby

Jeffrey Hurwitz

The orbit contains multiple tissues, each of which is subject to disease. A disease process in any tissue may have contiguous effects on neighboring tissues within this closed and compact compartment, in particular the optic nerve. Compression, stretching, or ischemia of the optic nerve will lead to rapid visual field and/or vision loss, which may or may not be irreversible. Tumor of virtually any orbital tissue can cause optic nerve compression. Likewise, hemorrhage, infiltration, infection, or vascular malformation may cause optic nerve compression. In the latter, if there is a lymphangiomatous component, compression may only occur when infection, for example, an upper respiratory viral systemic infection, results in temporary swelling of the orbital lesion. Tumors of the optic nerve itself are covered in Chapter 9: Optic Nerve.

Proptosis occurs when there is an increase in retrobulbar orbital volume. This can be acute or chronic. It may result from a variety of benign and malignant lesions. Benign tumors include vascular malformations and cysts. Orbital malignancy may be local (e.g., rhabdomyosarcoma, optic nerve glioma) or systemic (e.g., leukemia, neuroblastoma). Infectious causes of proptosis may also be acute (e.g., bacterial orbital cellulitis) or chronic (e.g., parasitic cyst). Acute inflammatory disease includes pseudotumor. As the globe translates forward for any reason, the optic nerve is stretched, resulting in serious vision loss. Surgical decompression of the orbit may be needed.

Figure 11.1 Orbital Dermoid

Orbital dermoids are common lesions noted of the anterior orbit in children. They arise in the locations of the frontozygomatic suture and, less commonly, the frontonasal sutures. During embryogenesis, dermal elements may get “pinched off” and reside in the suture lines. Superficial dermoids are easily palpable and generally grow with facial growth. Deeper dermoids may not be noted until later in childhood and may have intracranial extension through the suture with a mass on either side of the cranial vault, sometimes called “dumbbell dermoids.” The cysts’ walls have dermal elements and the contents can contain keratin hair follicles. Rupture by trauma, including surgery, can elicit a severe granulomatous response.

Figure 11.2 Lymphangioma

Lymphangiomas are benign lesions that have been more recently categorized as part of a spectrum of combined venous–lymphatic abnormalities. Recurrent proptosis and visual loss can occur through recurrent hemorrhages. The left image shows a child at baseline with an inferior orbital mass. With upper respiratory tract infection, dramatic swelling can occur (right image). Proptosis and visual loss may occur. Surgical extirpation or transcutaneous draining of affected areas may be needed.

Figure 11.3 Capillary Hemangioma

Capillary hemangiomas commonly occur on the lids and anterior orbit. Clinically, they range from small isolated lesions to larger tumors that can cause ptosis (as seen in this child’s left medial upper lid) and visual loss. There may or may not be an overlying “strawberry” lesion (Chapter 2: Lids and Adnexa, Figs. 2.17 and 2.18). Systemic considerations include the Kasabach-Merritt syndrome, a consumption coagulopathy associated with large hemangiomas. The natural history involves a proliferative phase in the first year of life followed by regression. Indications for treatment include amblyopia, proptosis, and optic neuropathy. Intralesional steroids are not recommended for deep lesions like the one shown here. Other treatment options include surgical excision, systemic steroids, or interferon.

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