Items tagged “orbit”
46 results found
Article
Abducens nerve
The abducens nerve is the sixth cranial nerve (CN VI). It is a motor nerve responsible for abduction of the eye (TA: nervus abducens or nervus cranialis VI). It courses from the abducens nucleus, located in the dorsal pons, up to the cavernous sinus, via a long cisternal segment that is prone to...
Article
Capillary hemangioma of the orbit
Capillary hemangiomas of the orbit, also known as strawberry hemangiomas, on account of its coloring, or orbital infantile hemangiomas, are the most common orbital tumors of infancy, and unlike orbital cavernous hemangiomas, they are neoplasms rather than vascular malformations.
Clinical presen...
Article
Idiopathic orbital inflammation
Idiopathic orbital inflammation, also known as orbital pseudotumor and non-specific orbital inflammation, is an idiopathic inflammatory condition that most commonly involves the extraocular muscles. Less commonly there is inflammatory change involving the uvea, sclera, lacrimal gland, and retrob...
Article
Phthisis bulbi
Phthisis bulbi, also known as end-stage eye, is an atrophic scarred and disorganized non-functioning globe that may result from a variety of severe ocular insults.
Epidemiology
In general, phthisis bulbi involves elderly patients, usually 65-85 years of age 7. Children and adolescents are onl...
Article
Retinoblastoma
Retinoblastomas are the most common intraocular neoplasm found in childhood and with modern treatment modalities, are, in most cases, curable.
On imaging, they are generally characterized by a heterogeneous retinal mass with calcifications, necrotic components and increased vascularization on D...
Article
Orbital mass
An orbital mass carries a wide differential.
Differential diagnosis
tumors
lymphoma
metastasis
lacrimal gland or duct tumors
rhabdomyosarcoma of the orbit
retinoblastoma
optic nerve meningioma
optic nerve glioma
schwannoma (of trigeminal or other cranial nerves except optic)
neurofibr...
Article
Ophthalmic artery
The ophthalmic artery is a branch of the supraclinoid (C6) segment of the internal carotid artery.
Gross anatomy
Origin
The ophthalmic artery arises medial to the anterior clinoid process as the internal carotid artery exits the cavernous sinus. It originates from the antero- or supero-medial...
Article
Orbital venous varix
Orbital venous varix (plural: varices) is an uncommon vascular malformation that is composed of enlarged single or multiple tubular venous channels within the orbit with direct communication to the systemic venous system.
Terminology
Orbital venous varices are divided into primary and seconda...
Article
Trilateral retinoblastoma
Trilateral retinoblastoma refers to the combination of retinoblastoma (usually bilateral) and pineoblastoma. This relationship highlights the close relationship between these highly aggressive small round blue cell tumors.
It affects only a minority of patients with retinoblastoma (1.5-5%) and ...
Article
Optic pathway glioma
Optic pathway gliomas are relatively uncommon tumors, with a variable clinical course and usually seen in the setting of neurofibromatosis type I (NF1). Histologically the majority are pilocytic astrocytomas.
They are characterized by imaging by an enlarged optic nerve seen either on CT or MRI....
Article
Tram-track sign (orbit)
Tram-track sign refers to the parallel thickening and enhancement around the optic nerve, and is most frequently seen in the setting of optic nerve meningioma. It may, however, also be seen in 1:
orbital pseudotumor
perioptic neuritis
orbital sarcoidosis
orbital leukemia
orbital lymphoma
o...
Article
Primary uveal malignant melanoma
Malignant uveal melanomas, also referred to as choroidal melanomas, are the most common primary tumor of the adult eye 3.
Epidemiology
Malignant melanoma of the uvea is the most common primary intraocular malignancy and is predominantly seen in the White population 5. The incidence of these t...
Article
Optic disc drusen
Optic disc drusen (ODD), or hyaline bodies, are a relatively common entity usually found incidentally on CT or on follow-up of abnormal fundoscopy.
Epidemiology
Optic disc drusen are identified radiographically in up to 0.3-3.7% of the population and are frequently bilateral 1,4,5. They are ty...
Article
Choroidal osteoma
Choroidal osteomas are rare benign calcific masses of the globe.
Epidemiology
Choroidal osteomas are typically found in young Caucasian women 1. A number of familial cases have been reported 3.
Clinical presentation
These lesions are usually unilateral (75%), and result in painless and gra...
Article
Silent sinus syndrome
The silent sinus syndrome represents maxillary sinus atelectasis that results in painless enophthalmos, hypoglobus and facial asymmetry 1-3. Some authors restrict the term to patients with no history of sinusitis, trauma or surgery 2. Some authors suggest that is part of the spectrum of chronic ...
Article
Retinoblastoma (staging)
Retinoblastoma staging can be via a number of systems with various end-points and multiple systems are often used concurrently.
Staging
Reese Ellsworth classification
The Reese Ellsworth classification is assessed with fundoscopy and aims at predicting the chance of preserving the eye with ex...
Article
Orbital lymphoma
Primary lymphoma of the orbit is one of the most common orbital tumors and accounts for as much as half of all orbital malignancies. It is a B-cell non-Hodgkin lymphoma, and in most cases arises from mucosa-associated lymphoid tissue (MALT).
Epidemiology
Orbital lymphomas account for only 2% o...
Article
Orbital cavernous venous malformation
Cavernous venous malformations of the orbit, also known as cavernous hemangiomas, are the most common vascular lesion of the orbit in adults.
It is important to note that according to newer nomenclature (ISSVA classification of vascular anomalies) these lesions are merely known as slow flow ven...
Article
Orbital vascular lesions
Orbital vascular lesions may be difficult to distinguish on imaging. However, the following conditions have been described:
arteriovenous malformation (AVM)
capillary hemangioma
cavernous hemangioma
orbital lymphangioma / lymphangiovenous malformation / venolymphatic malformation
orbital ve...
Article
Intraconal orbital compartment
The intraconal orbital compartment or intraconal space is the conical space within the orbit and musculofascial cone, the base of which is anterior and is formed by the posterior half of the globe. The sides are formed by the extraocular muscles and their surrounding fascia which pass posteriorl...
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