Items tagged “eye”

103 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

Calcification of the globe (differential)

Calcification of the globe has many causes, varying from benign to malignant. When calcification is seen in the posterior half of the globe, it could relate to any of the layers (scleral, choroidal or retinal), as it is not possible to separate them out on CT. Retinal drusen: 1% population at ...
Article

Ectopia lentis

Ectopia lentis refers to subluxation or dislocation of the lens of the eye secondary to dysfunction or disruption of zonular fibres. It is most commonly due to trauma. The commonest atraumatic aetiologies are Marfan syndrome and homocystinuria. Pathology Aetiology trauma systemic and syndrom...
Article

Orbit

The orbits are two bony sockets at the front of the face that primarily house and protect the eyes and associated structures.  Terminology Ocular or optic refers specifically to the globe (eyeball). Orbital refers to all the contents of the bony orbit, encompassing both the intra and extraocul...
Article

Idiopathic orbital inflammation

Idiopathic orbital inflammation, also known as orbital pseudotumour 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 retro...
Article

Retinal detachment

Retinal detachment is a detachment of the neurosensory retina from the underlying pigmented choroid. Apposition of the retinal pigmented epithelium to the overlying retina is essential for normal retinal function. Terminology There are numerous subtypes of retinal detachment 5: rhegmatogenous...
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 characterised by a heterogeneous retinal mass with calcifications, necrotic components and increased vascularisation on D...
Article

Superior orbital fissure

The superior orbital fissure is the communication between the cavernous sinus and the apex of the orbit. It is straddled by the tendinous ring which is the common origin of the four rectus muscles (extraocular muscles). Gross anatomy Boundaries medial: body of sphenoid superior: lesser wing ...
Article

Tendinous ring

The tendinous ring, also known as the annulus of Zinn, is the common origin of the four rectus muscles (extraocular muscles). The tendinous ring straddles the lower, medial part of the superior orbital fissure. It attaches to a tubercle on the greater wing of the sphenoid bone (at the margin of...
Case

Retinal detachment

  Diagnosis certain
Frank Gaillard
Published 22 May 2008
74% complete
MRI
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

Leukocoria

Leukocoria (also spelt as leucocoria or leukokoria) refers to an abnormal white reflection from the retina of the eye. Despite its colour, the reflection is related to the familiar red-eye effect. Usually, when a light is shone through the iris, the retina appears red to the observer. In leukoco...
Case

Enophthalmos due to anorexia nervosa

  Diagnosis almost certain
Frank Gaillard
Published 02 Jan 2009
65% complete
CT
Article

Coloboma

Coloboma is a collective term encompassing any focal discontinuity in the structure of the eye and should not be confused with staphylomas which are due to choroidal thinning.  Terminology While coloboma is the collective term for any focal discontinuity in the eye's structure, many people use...
Case

Multiple myeloma - orbit

  Diagnosis certain
Frank Gaillard
Published 15 Apr 2009
80% complete
CT
Case

Coats disease of the eye

  Diagnosis almost certain
Michael Sargent
Published 22 Apr 2009
56% complete
Ultrasound CT MRI
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 tumours. It affects only a minority of patients with retinoblastoma (1.5-5%) and...
Article

Optic pathway glioma

Optic pathway gliomas are relatively uncommon tumours, with a variable clinical course and usually seen in the setting of neurofibromatosis type I (NF1). Histologically the majority are pilocytic astrocytomas. They are characterised 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 pseudotumour perioptic neuritis orbital sarcoidosis orbital leukaemia orbital lymphoma ...
Article

Morning glory syndrome (eye)

Morning glory disc anomaly (MGDA), also known as morning glory syndrome, is a rare congenital malformation of the optic nerve which is frequently associated with midline abnormalities of the brain and skull 1. Epidemiology Morning glory disc anomaly is rare and is more commonly found in female...

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