MRCOPHTH Flashcards
1
Q
Acute zonal occult outer retinopathy (AZOOR)
A
- an idiopathic conditions which may be precipitated by punctate inner choroiodapthy (PIC), multifocal choroiditis (MIC) or multiple evasnescent white dot syndrome (MEWDS)
- it is characterized by a rapid loss of visual field which cannot be explained by the ophthalmoscopic changes
- majority of the sufferers are healthy young white myopic females.
- initial presentation is with photopsia and increased blind spot in the presence of normal visual acuity. Later, the visual field is decreased with decreased visual acuity.
- fluorescein angiography is not helpful as it is normal or might only show the precipitation condition initially.
- In electrophysiology, the electro-oculogram (EOG) light rise is often reduced and the ERG is usually very abnormal.
- there is no effective treatment. In some patients, the vision returns spontaneously.
2
Q
Idiopathic polypoidal choroidal vasculopathy (IPCV)
A
- is also known as posterior uveal bleeding syndrome and multiple recurrent serosanguineous REP detachment syndrome.
- although originally described in black hypertensive females in middle age. It is now been recognized in other races.
- the characteristic lesion appears to be an inner choroidal vascular network of vessels ending in an aneurysmal bulge or outward projection.
- recurrent and multiple REP detachments with or without the associated subretinal bleeding (posterior uveal bleeding syndrome) may then occur.
- the absence of drusen, retinal vascular disease and intraocular inflammation is characteristic of the condition. Vitreous haemorrhage may also occur.
- the lesions were originally described to be peripapillary in location, but pure macular lesions have also been reported.
- indocyanine green angiography is most helpful in identifying polyps.
- it has a better prognosis than other causes of haemorrhagic detachments of the retina. Direct laser therapy to the lesion appears to carry a better prognosis in IPCV compared to laser therapy of CNV in AMD patients.
3
Q
Stickler’s syndrome
A
- autosomal disorders
- associated with abnormal production of type II collagen
- ocular features include myopia, cataracts, strabismus, and optically-empty vitreous traction and lattice degeneration
- multiple retinal breaks occurs in more than 75% of the patients.
- systemic manifestation include maxillary and mandibular hypoplasia, cleft palate, abnormal uvula, neurosensory hearing loss and skeletal abnormalities with joint hyperextensibility, and marfanoid habitus
4
Q
Difference between ARN and PORN
A
- both conditions are associated with herpes virus chiefly herpes simplex and zoster
- both conditions can lead to retinal detachment
- ARN is seen both in healthy and immunocompromised patients whereas PORN is seen exclusively in AIDS or immunocompromised patients
- vitritis is often severe in ARN but is usually minimal or absent in PORN
- ARN responds to intravenous acyclovir but PORN responds poorly and PORN patients usually have poorer eventual visual outcome
5
Q
Vigabatrin
A
- indicated only when all other appropriate antiepileptic drug combinations have proved ineffective or poorly tolerated
- is an GABA transaminase inhibitor
- indicated as first line therapy only in infantile spasm
- about 1/3 of epilepsy patients using it have characteristic visual field defects which can vary from asymptomatic to severe and disabling
- the defect is not reversible even with cessation of the therapy
- the cause of the visual field loss is unknown
- not recommended in patients with pre-existing visual field defects
6
Q
Familial exudative vitreoretinopathy
A
- FEVR is normally an autosomal dominantly inherited disease but X-linked inheritance has been described.
- although both eyes are affected, the degree of involvement may be very asymmetrical.
- the fundus appearances may be confused with retinopathy of prematurity (ROP)
- it is characterized by peripheral areas of avascularity in the peripheral retina, almost indistinguishable from ROP. The lack of history of premature birth, low birth weight, or oxygen therapy differentiates this condition from retinopathy of prematurity.
- dragging of the retina temporally with vessel straightening, subretinal exudation, cicatrization and retinal detachment are all features of this condition. Complications include neovascularisation in the peripheral retina.
- treatment with cryotherapy to neovascular areas, and scleral buckling and vitrectomy procedures for tractional detachments have all been used in the treatment.
- relentless progression is uncommon. Visual impairment tends to occur early and it is rare to lose vision after the age of 30 unless the patient develops tractional retinal detachment.
7
Q
Oguchi disease
A
- is a form of congenital stationary night blindness
- is characterized by a golden/grey-white discoloration of the retina giving a metallic sheen to the back of the eye. This disappeared when the fundus was viewed after some time in the dark and has become known as the Mizuo-Nakamura phenomenon.
- visual acuity, colour vision and visual fields are usually normal in Oguchi disease.
- two genes involved in Oguchi disease have been identified and include: arrestin, a gene located in the region of the distal arm of chromosome 2q, and rhodopsin kinase. The arrestin mutations are more common in Japanese Oguchi disease, and rhodopsin kinase in European Oguchi disease.
- patients are asymptomatic in light, but are night blind.
- dark adaptation shows extremely retarded rod function.
8
Q
Retinal crystals are seen in
A
- drug-induced:
- tamoxifen
- canthaxanthin
- talc
- methoxyflurane
- metabolic disorders
- cysintonosis
- primary oxalosis type 1
- Others
- Bietti retinal dystrophy
- Sjorgren-Larsson syndrome
9
Q
Shaken baby syndrome
A
- typically occurs in children less than 3 years of age and results from violent shaking
- there is no external eye injury but the posterior segment shows retinal haemorrhages (both intra and subretinal) and vitreous haemorrhage
- skull fracture is uncommon but CT scan reveals subarachnoid or intracerebral haemorrhages
- vomiting, lethargy and focal neurologic findings are common
- the visual prognosis is poor due to macular scarring, vitreous haemorrhage and retinal detachment
10
Q
In central retinal artery occlusion and ophthalmic artery occlusion
A
- both give cherry-red spot in the acute phase
- both causes relative afferent pupillary defect
- in ophthalmic artery occlusion, the a and b waves on the ERG are abnormal due to insult to the outer and inner retina
- in ophthalmic artery occlusion, both the choroidal and retinal circulation are delayed
- in ophthalmic artery occlusion, the REP is disturbed resulting in pigmentary changes at a later date
11
Q
Aberrant regeneration of the third nerve (oculomotor synkinesis):
A
- features of congenital third nerve palsies and those caused by tumours, aneurysms and trauma but not those due to ischaemic ophthalmoplegia
- known features include: elevation of the upper lid on attempted adduction or depression of the eye, retraction of the globe on attempted depression or elevation of the eye
- constriction of the pupil on attempted adduction or depression
12
Q
Abnormal material in the vitreous include
A
- pseudoexfoliation in pseudoexfoliation syndrome
- haemosiderin from vitreous haemorrhage
- amyloidosis in familial amyloidosis
- calcium in asteroid hyalosis
13
Q
Absent of pupil response to direct and consensual light response
A
- occur when the iris of the affected eye is paralysed and this occur in
- blunt trauma
- third nerve palsy
- atropine
- siderosis bulbi
14
Q
Acquired syphilis
A
- causes painless ulcer in the primary stage which is highly infectious
- in the secondary stage, the patient may develop a rash which is non-infectious
- uveitis can occur in the secondary stage
- treatment is with penicillin
- Interstitial keratitis is a feature of congenital syphilis
15
Q
Acute posterior multifocal placoid pigment epitheliopathy (APMPPE)
A
- typically affects healthy young adults who presents with sudden onset central or paracentral visual loss after a flu like illness
- scattered, patchy creamy lesions at the level of the retinal pigment epithelium layers
- the lesions fade after one to two weeks leaving behind granular pigmentary changes
- fluorescein angiography shows early blockage of choroidal circulation by these lesions but in the late phase the lesions show late staining
- other findings: uveitis, serous retinal detachment, cerebral vasculitis, cerebrospinal fluid pleocytosis, headache, hearing loss and tinnitus
- spontaneous resolution is common and systemic steroid has not been shown to be useful
16
Q
Adenocystic carcinoma of the lacrimal gland:
A
- the most common malignant tumour of the lacrimal gland
- has no well-defined capsule
- invade perineural tissue causing pain and metastasise early to the brain
- 5 histologic patterns: cribriform (Swiss cheese and of lower grade), solid (basaloid), sclerosing, comedocarcinomatous and tubular (ductal)
- treatment is with orbital exenternation and removal of involved bone
- the prognosis is very poor
17
Q
Albinism
A
- can be of oculocutaneous or ocular types
- oculocutaneous types can be divided into tyrosinase-positive and tyrosinase-negative types. Hair bulb test is useful to differentiate the two within the first three years of life
- is associated with abnormal platelet aggregation in Hermansky-Pudlak syndrome
- poor vision is usually due to macular hypoplasia
18
Q
Angioid streaks occur in many conditions including:
A
- pseudoxanthoma elasticum
- Ehlers-Danlos syndrome
- sickle cell disease
- Paget’s disease
19
Q
Ankylosing spondylitis:
A
- inflammatory disorders of spinal joints
- 90% have the HLA-B27 halotype
- systemic features include peripheral arthritis, uveitis, aortic valve incompetence and chronic inflammatory bowel disease
- the condition is commoner and more severe in males than females
- in the spine, the inflammation begins at the site where ligaments are attached to vertebral bone (the entheses), however, signs may occur before the patients complain of any symptoms.
20
Q
Anterior capsule removal:
A
capsulorrhexis is a more difficult technique to master than capsulotomy but produces a stronger edge and causes less displacement of the lens due to more equal distribution of force should the capsule undergoes fibrosis
21
Q
Anti-glaucoma medications
A
- beta-blocker causes slowing of heart rate but is not contra-indicated in primary heart block ( prolonged PR interval)
- beta-blocker should be avoided in patients taking centrally acting calcium channel blocker such as verapamil. Nifedipine acts peripherally
- acetazolide contains structure similar to sulphonamide and should be avoided in those who is allergic to it
- acetazolamide causes diuresis and loss of potassium, supplement may be needed latanoprost is contraindicated in patients with intraocular inflammation
*
22
Q
Benign intracranial hypertension:
A
- the eye movement is usually normal but there may be sixth nerve palsy
- the CT scan should be normal
- in young women on contraceptive pill, brain scan is important to exclude saggital sinus thrombosis which may presents with similar pictures
- optic nerve fenestration is indicated if there were evidence of optic nerve dysfunction
- the condition can be treated with diuretic and repeated lumbar puncture. Ventricular-peritoneal is rarely required.
23
Q
Biopsy report in rheumatoid arthritis include
A
- posterior scleritis
- episcleral necrotic tissue
- vasculitis
24
Q
Breaks in Descemet’s membrane occurs in
A
- trauma as in forcep delivery
- keratoconus
- congenital glaucoma
25
Q
Central retinal artery occlusion:
A
- rubeosis iridis occurs in about 10% of patients
- rarely retinal neovascularization is seen
- atrial fibrillation is a cause of embolus which may lead to retinal artery occlusion
- delayed hyperfluorescence of choroidal circulation is a feature of ophthalmic artery occlusion
- optic atrophy occurs due to loss of ganglion cell layers and these may take months to develop
26
Q
Central serous retinopathy
A
- the patient usually presents with distorted vision without significant central visual loss
- Amsler’s chart testing usually shows distortion of lines or scotoma
- the image appears smaller than the unaffected eye
27
Q
Choroideremia
A
- X-linked recessive disorder characterised by progressive degeneration of the choriocapillaris and RPE
- typically affects male
- onset is in the first decade with night blindness
- central vision is affected late
- ERG shows reduced a and b waves female carriers may shows peripheral pigmentary changes
28
Q
Coat’s disease
A
- non-hereditary, unilateral congenital disorder characterised by abnormal telangiectatic and aneurysmal retinal vessels in the peripheral retina
- male outnumber female by 3 to 1
- presents with leukocoria and strabismus. Untreated can lead to exudative retinal detachment, glaucoma and pthisical eye
- laser is useful in destroying the abnormal blood vessels
29
Q
Colour defect:
A
- macular problems usually cause loss of blue/yellow colour discrimination
- optic nerve defects tend to result in red / green colour defect
30
Q
Congenital glaucoma secondary to:
A
- aniridia
- Sturge-Weber’s syndrome
- anterior chamber angle cleavage syndrome such as Peter’s anomaly or Axenfeld’s syndrome
31
Q
Corneal dystrophy:
A
- inherited and bilateral conditions
- the following abnormal substance are documented:
- glycoaminoglycan (macular dystrophy, fleck dystrophy)
- hyaline degeneration (granular dystrophy)
- amyloid (lattice dystrophy)
- lipid (fleck dystrophy)
- cholesterol (central crystalline dystrophy)
32
Q
Cyclosporin A
A
- is the product of the fungus Tolypocladium inflatum
- inhibits T cell activation by stopping the expression of receptors on T lymphocytes that recognize the DR antigen found on antigen presenting cells
- has poor tissue penetration when applied topically
- is the drug of choice in patients with Behcet’s disease
- causes nephrotoxicity as the main side effect which is dose-dependent
- other side effects include: hypertension, hypertrichosis, gastrointestinal upset, gingival hyperplasia, anaemia and raised ESR
33
Q
Deafness occurs in
A
- Cockayne’s syndrome: premature ageing, dwarfism, bird like facies and retinal degeneration
- Altroem’s syndrome: retinitis pigmentosa, deafness, obesity and diabetes mellitus
- Alport’s syndrome: haematuria, sensorineural deafness, anterioir lenticonus
- Usher’s syndrome: neurosensory deafness, retinitis pigmentosa
34
Q
Dendritic ulcer of the cornea can be treated with:
A
- iodination
- debridement
- topical or systemic acyclovir
35
Q
Dissociated vertical deviation
A
- refers to the phenomenon in which the eye elevates when the amount of light entering it is reduced
- usually begins between 2 to 3 years of age
- associated with infantile esotropia
- the binocular vision is usually poor
- surgery of choice is either superior rectus recession or Faden’s procedure
36
Q
Duane type A
A
Brown’s classification
Type A: limited abduction and less marked adduction limitation
Type B: limited abduction and normal adduction
Type C: limitation of adduction exceeds the limitation of abduction
- widening of the palpebral fissure on abduction
- globe retraction and palpebral narrowing on adduction
- face turns to the affected side is common
- caused by innervation of the lateral rectus by a branch of third nerve in place of absent sixth nerve
- sixth nerve nucleus aplasia has been documented
37
Q
Enlarged corneal nerves occur in
A
- multiple endocrine adenomatosis
- keratoconus
- ichthyosis
- Refsum’s disease
- Fuchs’ corneal dystrophy
- neurofibromatosis
- leprosy
- trauma
- congenital glaucoma
- failed corneal graft
- keratoconjunctivitis sicca
- advanced age
- acanthamoeba keratitis
*
38
Q
Giant cell arteritis
A
- disease of the elderly
- sudden, painless and profound visual loss
- female more susceptible than male
- headache, low grade fever, anorexia, weight loss, tenderness upon brushing hair and jaw claudication
- ESR and C-reactive proteins are always raised but not diagnostic of the condition
- diagnosis is base on biopsy which reveal fragmentation of the internal elastic lamina and giant cell infiltration of the tunica media of the artery. However, giant cells are not essential for diagnosis.
39
Q
Goldenhar’s syndrome:
A
- is a type of hemifacial microsomia
- sporadic occurrence
- facial asymmetry with mandibular hypoplasia
- preauricular appendages, malformation of the ear, hearing loss caused by external ear lesions
- ocular features: epibulbar dermoids, limbal dermoids, eyelid colobomas and subcutaneous dermoids of the lids
40
Q
Heimann-Bielschowsky phenomenon
A
a type of monocular nystagmus that occurs due to longstanding poor vision in one eye with amblyopia, optic neuropathy, or dense cataract
41
Q
Heterochromic cyclitis
A
- chronic uveitis associated with cataract and glaucoma
- glaucoma develops in 20% of patients
- iris atrophy causes transillumination
- Amsler’s sign occurs during cataract extraction and is due to wispy iris vessels which extends from the iris to the trabecular meshwork and do not cause anterior synechiae
- is resistant to steroid treatment
42
Q
Histological staining:
A
- Giemsa stain can demonstrate inclusion body such as chlamydia
- osmium tetroxide is used to fix and stain myelin for electron microscopy
- yeast and fungi can be stained with Fuelgin’s stain, PAS, Luxol blue fast and Gomori methenamine silver
- eosin stains the cytoplasm pink whereas haematoxylin stains the nuclei blue
43
Q
Holme-Adie’s pupil
A
- there is light-near dissociation however there may be delayed or absent pupil reaction to both
- the condition is usually unilateral
- women are affected more often than men
- due to paralysis of the ciliary muscle, the accommodation is impaired
- denervation hypersensitivity is demonstrated by constriction to 2.5% methacholine and 0.1% pilocarpine
44
Q
Hypotony:
A
- occurs when the intraocular pressure is sufficient low to compromise the ocular function usually below 6 mmHg
- may be caused by decreased aqueous production or excessive aqueous drainage
- can results in:
- corneal oedema
- cataract formation
- uveal effusion
- macular oedema
- disc oedema
- choroidal folds
- choroidal detachment
45
Q
Hypoxic damage in diabetic mellitus is suggested by
A
- cotton-wool spots
- extensive IRMA
- vascular bleading
- extensive retinal haemorrhages
- iris neovascularization
46
Q
In blow-out fracture
A
- the orbital rim may be fracture or intact. In the former a step can be felt
- occur only when the air sinuses have develop
- surgical emphysema is a feature
- although typically cause problem with upgaze, the horizontal recti have connective tissue that extends to the orbital floor and therefore horizontal movement may be impaired to some extent
- the infraorbital nerve is involved but the nerve does not supply the tip of the nose which is by nasociliary nerve
47
Q
In corneal graft:
A
- the epithlium, keratocytes, nerves and epithelium will eventually be replaced by the host tissue
- the endothelium does not regenerate and therefore will remains that of donor.
- the descemet’s membrane is produced by the endothelium and will therefore remains that of donor
48
Q
Indications for subretinal fluid drainage include:
A
- bullous detachment making hole or tear identification difficult
- immobilized retina
- raised intraocular pressure
- inferior retinal detachment
49
Q
Inferior oblique recession:
A
- a weakening procedure
- is performed in the following situation: primary inferior oblique overaction as in V-pattern esotropia or secondary inferior overaction as in ipsilateral superior oblique palsy or contralateral superior rectus palsy
- is more difficult to perform than myectomy as the muscle needs to be reattached posteriorly
50
Q
Intravitreal gas injection:
A
- can cause retinal tear and cataract
- C3F8 has a longer half life than SF6 and also more expansile. C3F8 typically expands to 4 times its volume where as SF6 only 2 to 3 times and therefore C3F8 also causes more significant increase in intraocular pressure than SF6
51
Q
Investigation of sarcoidosis
A
- chest X-ray typically shows bilateral hilar lymphadenopathy, there may also be interstitial infiltrate
- ACE concentration is increased
- conjunctival biopsy may show non-caseating granuloma
- serum calcium may be raised in sarcoidosis
- gallium scan shows increase in parts of body affected by sarcoidosis
52
Q
Kayser-Fleishcer’s ring
A
- occurs in Wilson’s disease and intraocular copper foreign body
- the ring is caused by copper deposited in Descemet’s membrane which may be orange, brown, green- brown or grey in colour
- it begins superiorly then inferiorly and finally circumferentially
- regresses with D-penicillamine treatment
53
Q
Keratoconus occurs in
A
- connective tissue disorders such as Ehlers-Danlos’s syndrome and Marfan’s syndrome
- atopic eye conditions such as atopic keratoconjunctivitis
- Down’s syndrome
54
Q
Laser:
A
- green light is not absorbed by xanthophyll and therefore it is theoretically more advantageous to use green laser in the macular area
- diode laser penetrate vitreous haemorrhage well and is therefore ideal in vitreous haemorrhage
- YAG laser is colourless and therefore require neodymium to give it red colour for targeting
- used in ophthalmic practice is classified as type IV laser
55
Q
Leber’s optic neuropathy
A
- a mitochondrial inherited disease
- bilateral loss of central vision which is severe and painless
- typically in the second decade of life
- classic early picture shows a triad of circumpapillary telangiectatic microangiopathy, pseudoedema of the disc and absent fluorescein staining
56
Q
Many drugs have been implicated in optic neuropathy, the following are the better known:
A
- anti-tuberculous: ethambutol and isoniazid
- chloramphenicol
- digitalis
- oral hypoglycaemic agents: chlopropamide and tolbutamide
- chloroquine
- disulfirum
- D-penicillamine
57
Q
Marfan’s syndrome:
A
- autosomal dominant condition
- caused by incorrect expression of a gene product for 350kD glycoprotein known as fibrillin which is responsible for the extracellular microfibrol network. Type I collagen abnormality is seen in osteogenesis imperfecta
- 80% have lens subluxation which is typically displaced up and out
- lenticular myopia with normal axial length is a feature
- unlike homocystinuria, the patient is mentally normal
58
Q
Measles:
A
- is a paramyxovirus containing RNA
- causes Koplik’s spots on the conjunctiva and caruncle
- causes acute catarrhal conjunctivitis
- causes punctate keratitis which is self-limiting in developed countries but in the presence of malnutrition especially vitamin A deficiency, blinding keratitis can occur
- subacute sclerosing panencephalitis tends to occur in children who acquire measles before one year of age. It is characterized by progressive neurological deficit with dementia, myoclonus and focal signs causing death.
59
Q
Melanocytoma
A
- benign, highly pigmented tumour arising from melanocytes
- most commonly found in optic nerve head
- histologically shows plump polyhedral cells
- equally sex incidence
- commoner in black population
- usually asymptomatic but may show enlargement of blind spots
- 50% have associated choroidal naevus
- rarely the tumour shows necrosis, vascular obstruction and optic nerve compression
60
Q
Mesodermal dysgenesis:
A
- Axenfeld’s syndrome is associated with posterior embryotoxon and iris strands extending onto the cornea. Iris hypoplasia is a feature of Reiger’s anomaly
- Axenfeld’s syndrome is an autosomal dominant disorder
- Rieger’s anomaly is associated with posterior embryotoxon, prominent iris processes and iris stroma atrophy. Rieger’s syndrome is Rieger anomaly plus skeletal, facial, cranial and dental anomalies
- Peter’s anomaly consists of bilateral central corneal opacity due to defects in the posterior stroma. 50% of cases have glaucoma
61
Q
Microangiopathy in diabetes mellitus is characterised by
A
- microvascular obstruction and non-perfusion of capilaries
- retinal capillary microaneurysms
- absent membrane thickening
- loss of pericytes
- intraretinal microvascular abnormality
62
Q
Mutton fat keratic precipitates occurs in chronic granulomatous uveitis and seen in
A
- tuberculosis
- fungal
- leprosy
- syphilis
- sarcoidosis
- juvenile xanthogranuloma
- histiocytosis X
- sympathetic ophthalmia
- Vogt-Koyanagi-Harada syndrome
- toxoplasmosis
*
63
Q
Nystagmus
A
- see-saw nystagmus is seen with bitemporal hemianopia
- down-beat nystagmus occurs with lesion in the cervico-medullary junction at the foramen magnum
- manifest latent nystagmus is a type of horizontal jerk nystagmus which increases in amplitude when one eye is covered. It occurs in strabismus, amblyopia or uniocular pathology such as cataract
- gaze-evoked potential is not specific for cerebellar lesion, it occurs when the eyes are unable to maintain an eccentric gaze position through weakness of muscle tone in the agonist muscle
- convergence retraction nystagmus occurs with mid-brain tumours such as pinealoma
64
Q
Ocular bobbing
A
- conjugate involuntary recurrent downward movement of the eyes
- rapid downward movement with a slower return to the neutral position
- absent horizontal movements
- occurs in patients with acute pontine lesion who are either comatose or locked-in state
- can occur with tumour in the pontine
154
Q
Cerebral Malaria
A
156
Q
Early Visual Milestones
A
157
Q
Normal Visual Development
A
158
Q
Eye muscles
A
159
Q
Treatment of Childhood Glaucoma
A
160
Q
Secundary Glaucomas
A
