ABSTRACT
The orbit, or enclosure for the eye and associated muscles, nerves, and vasculature, is the conical cavity outlined by the periorbita. Orbital cellulitis typically has a sudden onset of unilateral protrusion of third eyelid, exophthalmos, and conjunctival swelling and hyperemia. Diseases of the orbit produce signs by altering the volume of the orbit and/or the function of orbital structures. Alterations in the volume of the orbit produce exophthalmos, enophthalmos, or deviation of the globe. A slowly progressive exophthalmos with minimal pain is highly suggestive of orbital neoplasia. Orbital neoplasia typically presents with a unilateral, nonpainful, slowly progressive exophthalmos with decreased retropulsion of the globe. Due to the malignant nature of most orbital tumors, excision is not curative but debulks the lesion and provides a diagnosis. Primary orbital tumors that are isolated may respond to orbital exenteration. Exenteration of the orbit rather than enucleation is indicated for neoplasia and involves removal of the globe and orbital contents.
