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
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
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
Published
15 Apr 2009
80% complete
CT
Case
Coats disease of the eye
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...