Search results for “ophthalmology”
227 results
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
Pituitary macroadenoma
Pituitary macroadenomas are the most common suprasellar mass in adults, and responsible for the majority of transsphenoidal hypophysectomies. They are defined as pituitary adenomas greater than 10 mm in size and are approximately twice as common as pituitary microadenomas.
On imaging, they usu...
Article
Osteogenesis imperfecta classification
Several forms of osteogenesis imperfecta (OI) have been classified, representing a wide variation in appearance and severity, and clinical features vary widely not only between types but within types.
Classification
Osteogenesis imperfecta was initially classified by type according to a scheme...
Article
Orbital blow-out fracture
Orbital blow-out fractures occur when there is a fracture of one of the walls of orbit but the orbital rim remains intact. This is typically caused by a direct blow to the central orbit from a fist or ball.
Epidemiology
The blow-out fracture is the most common type of orbital fracture and is u...
Article
Takayasu arteritis
Takayasu arteritis (TAK), also known as idiopathic medial aortopathy or pulseless disease, is a granulomatous large vessel vasculitis that predominantly affects the aorta and its major branches. It may also affect the pulmonary arteries. The exact cause is not well known but the pathology is tho...
Article
Target sign (disambiguation)
There are many bull's eye signs, many also called target signs:
Gastrointestinal
intussusception: see target sign of intussusception
barium studies 2
aphthoid ulcers: earliest lesion seen in Crohn disease
gastric lymphoma with central ulceration 4
gastric adenocarcinoma with central ulcer...
Article
Primary cutaneous melanoma
Primary cutaneous melanoma is the most common subtype of melanoma, a malignant neoplasm that arises from melanocytes. Melanocytes predominantly occur in the basal layer of the epidermis but do occur elsewhere in the body. Primary cutaneous melanoma is by far the most common type of primary melan...
Article
Spontaneous intracranial hypotension
Intracranial hypotension, also known as craniospinal hypotension is a clinical entity that results from a cerebrospinal fluid (CSF) leak that almost without exception occurs from the spine, either into the epidural space or directly into veins in the setting of CSF-venous fistulas. It usually, b...
Article
Osteogenesis imperfecta
Osteogenesis imperfecta (OI) refers to a heterogeneous group of congenital, non-sex-linked, genetic disorders of collagen type I production, involving connective tissues and bones.
The hallmark feature of osteogenesis imperfecta is osteoporosis and fragile bones that fracture easily, as well a...
Article
Acute spinal cord ischaemia syndrome
Acute spinal cord ischaemia syndrome, also known as acute spinal cord infarction, is uncommon, but usually presents with profound neurological signs and symptoms, and the prognosis is poor.
Epidemiology
Acute spinal cord ischaemia syndrome represents only 5-8% of acute myelopathies 4,5 and <1...
Article
Orbital lymphoma
Primary lymphoma of the orbit is one of the most common orbital tumours 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% ...
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
Ochronosis
Ochronosis, or alkaptonuria (AKU), is a rare multisystem autosomal recessive metabolic disorder.
On imaging, the most particular presentation is on the spine, with osteoporotic bones and dense disc calcifications.
Terminology
The term ochronosis usually refers to the bluish-black discolourat...
Article
Optic neuropathy
Optic neuropathy is a broad term and can result from a variety of causes.
Pathology
genetic
Leber hereditary optic neuropathy
compression or trauma (traumatic optic neuropathy)
optic nerve sheath meningioma
progressive diaphyseal dysplasia
thyroid-associated orbitopathy
shear injury
sku...
Article
Granulomatosis with polyangiitis
Granulomatosis with polyangiitis (GPA), previously known as Wegener granulomatosis, is a multisystem necrotising non-caseating granulomatous c-ANCA positive vasculitis affecting small to medium-sized arteries, capillaries, and veins, with a predilection for the respiratory system and kidneys.
T...
Article
Oxalosis
Oxalosis is supersaturation of calcium oxalate in the urine (hyperoxaluria), which in turn results in nephrolithiasis and cortical nephrocalcinosis.
This article focus on the secondary oxalosis, please refer to primary oxalosis for a specific discussion on this entity.
Pathology
Calcium oxa...
Article
Viva technique
Viva technique is hugely important when sitting oral examinations. You must remember that the examiners may well have been examining for several days and for hours at a time. They will have shown their films many times and will know them backwards! Moreover, their films will be beloved, so do no...
Article
Cardiomegaly
Cardiomegaly is a catch-all term to refer to enlargement of the heart, and should not be confused with causes of enlargement of the cardiomediastinal outline, or enlargement of the cardiac silhouette.
Pathology
Aetiology
There are many aetiologies for cardiomegaly:
congestive heart failure
...
Article
Alzheimer disease
Alzheimer disease is a common neurodegenerative disease, responsible for 60-80% of all dementias, and imposing a significant burden on developed nations. It is associated with an accumulation and deposition of cerebral amyloid-β (Aβ) and is the most common cerebral amyloid deposition disease.
...
Article
Idiopathic intracranial hypertension
Idiopathic intracranial hypertension (IIH), also known as pseudotumour cerebri, is a syndrome with signs and symptoms of increased intracranial pressure but where a causative mass or hydrocephalus is not identified.
Terminology
The older term benign intracranial hypertension is generally frown...
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