opthalmoloy PT 1 2016 modif

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A 48-year-old white man presents to his optometrist with a 1-month history of blurred vision

in his left eye Visual acuity is 6/12 in the affected eye (6/6 in the other eye) Fundal

examination reveals some mottled pigmentary changes at the left macula, associated withsome macular oedema On closer inspection, both fundi revealed reddish-brown bands deep

to the retina radiating in a spoke-like pattern from the optic disc

The optician referred the patient to his GP, who noted loose skin folds with yellow striationsand puckering in the neck and flexor aspects of the joints

What is the most likely diagnosis?

orange-streaks are idiopathic in up to 50% of patients the remaining 50% have associations with

systemic disease The skin changes present on this patient’s neck and flexor surfaces are

typical of those seen with pseudoxanthoma elasticum (the classic plucked chicken

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Angioid streaks can be seen with Ehlers–Danlos syndrome, which is associated with

hyperelasticity of the skin and loose joints Marfan syndrome is also associated with angioidstreaks but is not associated with the skin changes described These lesions can also occur inpatients with Paget’s disease, unlikely in a 48-year old man In patients of Afro-Caribbean

descent, they can also be seen in sickle cell disease

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Which one of the following is a cause of second-order-neurone Horner syndrome?

Explanation

The answer is Pancoast’s tumour –

Horner syndrome is also known as oculo-sympathetic paresis and is characterised by

miosis, ptosis and anhydrosis Lesions along the sympathetic chain along the head and

neck region can cause these clinical appearances The causes of Horner syndrome can

vary with age, and can be elicited by thinking about lesions that could affect its path

The first-order (central) neurone descends from the hypothalamus to the cervical spine.The second-order (preganglionic) neuroneexits the spinal cord and heads towards the

head and neck It travels along its path with the cervical sympathetic chain, the brachialplexus, lung apices (Pancoasttumour) to synapse at the superior cervical ganglion This islocated near the angle of the mandible and is in close proximity to the common carotidartery

The third-order (postganglionic) neurone begins at the superior cervical ganglion and

travels along the wall of the internal carotid artery into the cavernous sinus Lesions

along its path affecting the internal carotid arteryor within the cranium can affect its

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Internal carotid artery aneurysm (Option C) is incorrect Lesions of the third-order neuroneaffect the internal carotid artery.

Syringomyelia (Option E) is incorrect The first-order (central) neurone descends from thehypothalamus to the cervical spine (ciliospinal centre of Budge), and can be affected by

syringomelia

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45524

A patient with controlled ocular myasthenia gravis develops an acute infection

Which one of the following antibiotics is contraindicated?

Explanation

The answer is Aminoglycosides –

Aminoglycosides are contraindicated in patients with myasthenia gravis as they are

known to interfere with and impair neuromuscular transmission

Macrolides (Option B) is incorrect Macrolides have been associated with anecdotal reports

of increased myasthenic weakness, although the mechanism is less clear, with rare publishedincidence

Metronidazole (Option C) is incorrect Metronidazole is very rarely associated with the

disease

Penicillins (Option D) is incorrect Penicillins have been associated with anecdotal reports ofincreased myasthenic weakness, although the mechanism is less clear, with rare publishedincidence

Quinolones (Option E) is incorrect Quinolones have been associated with anecdotal reports

of increased myasthenic weakness, although the mechanism is less clear, with rare publishedincidence

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The answer is Abnormal visual evoked potentials

-In optic neuritis, demyelination causes a reduction in the velocity of the propagation of

action potentials and so the VEP response is delayed The ERG is normal as the retina isunaffected

Abnormal electroretinogram (Option B) is incorrect The ERG measures retinal electrical

activity and is often used to validate the significance of an abnormal VEP response (ie if theVEP is abnormal but so is the ERG, then the VEP abnormality might be secondary to an eyecondition and be a false-positive for optic nerve disease)

Abnormal electro-oculogram (Option C) is incorrect The EOG measures the overall electricalactivity of the eye and is reduced in degenerative eye conditions affecting the pigment

epithelial layer, such as Best’s disease

Abnormal electroencephalogram (Option D) is incorrect An EEG is not an optimal

investigation for assessing vision impairment

Abnormal electronystagmogram (Option E) is incorrect The ENG is simply a method of

documenting nystagmus using the electrical charge of the eye

Abnormal visual evoked potentials (VEP)

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805

A diabetic 46-year-old man is found in the Diabetic Clinic to have reduced visual acuity

During a telephone referral to the Eye Clinic, the ophthalmologist asks if the patient has anyrisk factors for macular oedema

Which one of the following should the referring physician bring to his attention?

Explanation

Diabetic macular oedema

The Wisconsin Epidemiological Study showed that the incidence of macular oedema was 2–6% in background diabetic retinopathy (DR), 20–63% in preproliferative DR and 70–74% inproliferative DR The prevalence increased with greater duration of diabetes, higher

glycosylated haemoglobin and greater proteinuria levels

Background diabetic retinopathy

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Smoking, hypertension and previous cataract surgery have all been implicated in the

pathogenesis of age-related macular degeneration (ARMD), but smoking is regarded as themost important modifiable risk factor Important non-modifiable risk factors include whiteEuropean ethnicity and a positive family history Recent studies have pointed to genetic

differences in the complement pathway having an important role to play in the pathogenesis

of the condition

Treatment

Anti-vascular endothelial growth factor (anti-VEGF) therapies have recently been introducedfor the treatment of exudative (wet) ARMD, although the National Institute for Health andCare Excellence (NICE) appraisal process has allowed only limited use of such agents for thetime being, on the basis of cost-effectiveness

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During a routine insurance medical examination, a GP notices that a 30-year-old female

patient has absent ankle jerks and unequal pupils

Which one of the following is the most likely diagnosis?

Explanation

The answer is Holmes-Adie syndrome –

• Adie’s pupil can be attributed to a postviral degeneration in the ciliary ganglion

• The pupil is initially dilated, with a tonic reaction to light and sectorial vermiform

movements • The pupil is hypersensitive to 0.125% pilocarpine A normal pupil will be

unaffected by this weak dilution of pilocarpine, whereas an Adie pupil will constrict due

to denervation hypersensitivity

• The near vision is impaired by accommodative spasm, but this recovers in a few months

• The pupil sphincter later becomes fibrosed and the pupil miosed (‘little old Adies’)

• Holmes–Adie syndrome is the combination of Adie’s pupil with hyporeflexia and

typically occurs in women in this age group

Horner syndrome (Option B) is incorrect Horner syndrome is another cause of anisocoria(unequal pupils), but the affected pupil is smaller Horner syndrome is not typically

associated with abnormal deep tendon reflexes

IIIrd Nerve palsy (Option C) is incorrect Third nerve palsies do cause anisocoria and an

abnormally large pupil, but are mainly characterised by reduced ocular motility and an

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Argyll Robertson pupil (Option E) is incorrect Argyll Robertson pupils are bilateral small

pupils which constrict to accommodation, ie there is light-near dissociation (the pupils

accommodate but do not react)

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Cytomegalovirus (CMV) retinitis causes haemorrhages at the edge of areas of retinal

necrosis The lesions are usually along the vascular arcades and involve the macula late in thedisease The prognosis for life expectancy was very poor before the advent of HAART (highlyactive antiretroviral therapy) and CMV retinitis was often a harbinger of death in these

patients Nowadays patients can survive for many years with CMV retinitis, which can

periodically flare up and require treatment, usually with ganciclovir or foscarnet

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A 49-year-old woman with a history of systemic lupus erythematosus (SLE) presents with asudden decrease in vision in her left eye On examination her blood pressure is 155/85 mmHg.Ophthalmological examination reveals flame-shaped haemorrhages and retinal oedema

affecting the temporal region of the retina

Which one of the following is the most likely cause of her symptoms?

to be small, single-arm studies Retinal neovascularisation can increase the risk of vitreoushaemorrhage and retinal detachment, so ophthalmology follow-up is advised

Branch vs retinal vein occlusion:

The fact that only the temporal region has been affected fits with branch rather than centralretinal vein occlusion For branch retinal vein occlusion the blockage occurs before the laminacribrosa and not all venous drainage is affected, hence the flame haemorrhages affect only

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21100part of the retina

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809

A patient is examined in the Diabetic Clinic and found to have a vitreous haemorrhage, which

is precluding a view of his fundus He is admitted for bed rest After 3 days the fundus can bevisualised

What is the most likely diagnosis?

Explanation

Proliferative diabetic retinopathy

There must be a source for the bleeding, and the most likely source of bleeding in a diabeticpatient is fragile neovascular tissue

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An 82-year-old woman presents with sudden loss of vision in her left eye On further

questioning, she complains of a left-sided headache over the past few weeks, associated withtenderness of her head when she brushes her hair On examination, her vision is reduced tocounting fingers in the left eye A left relative afferent pupillary defect is present Fundoscopyreveals a pale, swollen left optic disc with some flame-shaped haemorrhages The right eye isentirely normal An urgent erythrocyte sedimentation rate (ESR) is elevated at 72 mm/hour.Which one of the following management options should be carried out first?

Explanation

Temporal arteritis

Arteritic ischaemic optic neuropathy is a devastating ocular complication of giant-cell

arteritis (GCA), presenting with sudden, painless loss of vision GCA should always be

suspected in a patient over the age of 50 who presents with a history of headache and scalptenderness Other systemic symptoms include jaw claudication, proximal joint and muscularaches, anorexia, weight loss and fever Examination reveals an afferent pupillary defect and aswollen optic disc The ESR is usually raised

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biopsy performed within the next week An ophthalmic review should be sought – any

subsequent visual field test may reveal an altitudinal or central field defect

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A 45-year-old woman is found by her optometrist to have band keratopathy and is referred

to the Eye Clinic

Which one of the following investigations is likely to be helpful in determining an underlyingcause?

Explanation

Band keratopathy

Band keratopathy is caused by calcium deposition in Bowman’s layer of the cornea It canresult from the degenerative phase of chronic eye diseases or from hypercalcaemia Patientswho present with band keratopathy should have a serum calcium and phosphate level drawnunless the deposition has been documented previously and a known underlying cause exists.Parathyroid hormone levels should be checked in otherwise idiopathic cases

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A 32-year-old woman with rheumatoid arthritis presents to the Rheumatology Clinic with acomplaint of severe pain and reduced vision in one of her eyes The medical specialist traineenotes that one eye is dusky red in colour and that the vision in this eye is reduced to 6/36.What is the appropriate management?

Explanation

The answer is The patient should be referred urgently to the ophthalmology clinic –

A red painful eye in an individual with a history of connective tissue disease should be

referred urgently to the Ophthalmology Clinic for urgent diagnosis and treatment

Scleritis and uveitis are diagnoses that must be ruled out and treated promptly for visualpreservation Often they are started on artificial tears or antibiotics as empiric treatment,which offer no benefit Further along in their management they may be investigated forother coexisting inflammatory diseases

The patient should be booked for an urgent CT scan (Option A) is incorrect CT scan is

unnecessary at the first instance, unless advised by the ophthalmologists following a full

ocular examination

The patient should be investigated urgently for coexisting inflammatory bowel disease

(Option B) is incorrect This is unnecessary unless the patient complains specifically of

associated gastrointestinal symptoms Even so, it is not usually an ‘urgent’ investigation

The patient should be booked for an urgent CT scan

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The patient should be started immediately on immunosuppressant therapy (Option C) is

incorrect Systemic immunosuppressant therapy is unnecessary at the first instance, unlessadvised by the ophthalmologist following full ocular examination and failure for ocular

disease control with topical therapy

The patient should be started on artificial tears (Option D) is incorrect Artificial tears whileused as an empiric treatment rarely offer benefit

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Preproliferative diabetic retinopathy

Large deep blot haemorrhages are a sign of retinal ischaemia and can be a precursor of

neovascularisation These are deeper than the flame-shaped haemorrhages that occur in theretinal nerve fibre layer Darker (because they are deeper) and larger haemorrhages are

suggestive of preproliferative retinopathy The other cardinal feature of preproliferative

diabetic retinopathy is venous beading

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37326

A 54-year-old man with a history of Type 1 diabetes and multiple microvascular complicationscomes to the Emergency Department for review He is complaining of diplopia which is

making it impossible for him to drive There are no other neurological symptoms On

examination he has an outward deviating right eye and a ptosis; the pupil does not look

particularly dilated

Which of the following is the most likely cause?

Explanation

The answer is Diabetes mellitus

All of the options listed are potential causes of third nerve palsy The lack of any neurologicalsymptoms, including headache makes all of the options apart from diabetes mellitus and

idiopathic third nerve palsy unlikely The lack of pupil dilatation also supports diabetes as themost likely underlying cause In this case an underlying mononeuritis may recover over thecourse of a number of weeks If there is any suspicion of a vascular cause, CT is the initial

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A 32-year-old woman presents to her GP with a 1-week history of decreased vision and pain

in her right eye She was previously fit and well, and has no significant previous ocular or

medical history

Examination reveals a visual acuity of 6/60 in the affected eye with a relative afferent pupildefect Ocular movements are full but painful There is red colour desaturation Fundal

examination is normal The remainder of the neurological examination is normal

Explanation

Optic neuropathy

Optic neuritis

Optic neuritis is characterised by a progressive loss of vision (typically over 1 week)

associated with pain on ocular movement and loss of colour vision It can be idiopathic or

secondary to multiple sclerosis, infections (eg measles, mumps, herpes zoster) or contiguousinflammation of the meninges, orbit or sinuses Typically, the condition is retrobulbar,

resulting in few fundal abnormalities (the patient sees nothing and neither do you!) Disc

swelling occurs more commonly in childhood cases, ie papillitis

Other optic neuropathies

An orbital tumour can compress the optic nerve, resulting in visual loss However, this

typically progresses over a longer time-span Ischaemic optic neuropathy typically affectsolder patients with a history of microvascular disease (non-arteritic) or giant-cell arteritis

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A diabetic patient with diplopia is found to have a IIIrd nerve palsy

Which one of the following clinical features suggests that urgent neuroimaging should becarried out?

Explanation

The answer is Pupil involvement –

The third cranial nerve has motor fibres to the levator palpabrae superioris, superior,

medial and inferior recti, inferior obliques as well as pupillomotor fibres to the iris

sphincter Depending on the cause of IIIrd cranial nerve palsy, the function of the iris

sphincter can either be spared or affected If the pupil is spared, an ischaemic cause is

more likely (check the individual’s likely cardiovascular profile, in this case diabetes

makes this more likely) If the pupil is involved, a compressive lesion must be suspected,particularly if there is associated pain This warrants urgent intracranial scan and, if

appropriate, onward referral to neurosurgery

Impaired adduction (Option A) is incorrect Impaired adduction is a manifestation of a IIIrdcranial nerve palsy but does not necessarily warrant urgent investigation (unlike pupil

involvement)

Impaired elevation (Option B) is incorrect Impaired elevation is a manifestation of a IIIrd

cranial nerve palsy but does not necessarily warrant urgent investigation (unlike pupil

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A 26-year-old man with AIDS is responding well to his initial course of triple therapy when hecomplains to his genitourinary physician of reduced vision and slight discomfort in his eyes.His CD4 count has recently improved from less than 50 to 800

Explanation

The answer is Immune reconstitution uveitis –

Immune reconstitution uveitis is the cause that is associated with recovery of the CD4

count In this condition a granulomatous uveitis appears as the immune system recovers

as a result of autoimmune mechanisms

Toxoplasmosis (Option A) is incorrect Toxoplasmosis can cause reduced vision in HIV, but isassociated with a very low CD4 count

Cytomegalovirus (Option B) is incorrect Cytomegalovirus can cause reduced vision in HIV,but is associated with a very low CD4 count

Optic neuritis (OptionC) is incorrect Optic neuritis can occur as a result of toxoplasmosis,cytomegalovirus and herpes zoster retinitis, but would not be high on the differential

diagnosis of this patient

Herpes zoster retinitis (Option E) is incorrect Herpes zoster infection can cause reduced

vision in HIV, but is associated with a very low CD4 count

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