tailieunhanh - Chapter 029. Disorders of the Eye (Part 18)

Orbital Cellulitis This causes pain, lid erythema, proptosis, conjunctival chemosis, restricted motility, decreased acuity, afferent pupillary defect, fever, and leukocytosis. It often arises from the paranasal sinuses, especially by contiguous spread of infection from the ethmoid sinus through the lamina papyracea of the medial orbit. A history of recent upper respiratory tract infection, chronic sinusitis, thick mucous secretions, or dental disease is significant in any patient with suspected orbital cellulitis. Blood cultures should be obtained, but they are usually negative. Most patients respond to empirical therapy with broad-spectrum IV antibiotics. Occasionally, orbital cellulitis follows an overwhelming course, with massive. | Chapter 029. Disorders of the Eye Part 18 Orbital Cellulitis This causes pain lid erythema proptosis conjunctival chemosis restricted motility decreased acuity afferent pupillary defect fever and leukocytosis. It often arises from the paranasal sinuses especially by contiguous spread of infection from the ethmoid sinus through the lamina papyracea of the medial orbit. A history of recent upper respiratory tract infection chronic sinusitis thick mucous secretions or dental disease is significant in any patient with suspected orbital cellulitis. Blood cultures should be obtained but they are usually negative. Most patients respond to empirical therapy with broad-spectrum IV antibiotics. Occasionally orbital cellulitis follows an overwhelming course with massive proptosis blindness septic cavernous sinus thrombosis and meningitis. To avert this disaster orbital cellulitis should be managed aggressively in the early stages with immediate imaging of the orbits and antibiotic therapy that includes coverage of methicillin-resistant Staphylococcus aureus. Prompt surgical drainage of an orbital abscess or paranasal sinusitis is indicated if optic nerve function deteriorates despite antibiotics. Tumors Tumors of the orbit cause painless progressive proptosis. The most common primary tumors are hemangioma lymphangioma neurofibroma dermoid cyst adenoid cystic carcinoma optic nerve glioma optic nerve meningioma and benign mixed tumor of the lacrimal gland. Metastatic tumor to the orbit occurs frequently in breast carcinoma lung carcinoma and lymphoma. Diagnosis by fine-needle aspiration followed by urgent radiation therapy can sometimes preserve vision. Carotid Cavernous Fistulas With anterior drainage through the orbit these produce proptosis diplopia glaucoma and corkscrew arterialized conjunctival vessels. Direct fistulas usually result from trauma. They are easily diagnosed because of the prominent signs produced by high-flow high-pressure shunting. Indirect fistulas or .