Ophthalmology

Question 1

what conditions are ocular emergencies

Answer 1

Central Retinal Artery Occlusion

Retinal detachment

Orbital cellulitis

Acute angle closure glaucoma

Giant cell arteritis

Question 2

measuring visual acuity

Answer 2

corrective glasses or contact lenses should be worn

pt 6 metres away from snellen chart

record as distance from chart/number of lowest line read

if can’t read top line at 6 metres move closer 1m at a time

if not perfect with corrected lenses then used pinholes to remove refractory error

Question 3

what is a logMAR

Answer 3

a more specialist chart for testing visual acuity where a logarithmic scale is used - used by ophthalmologists

Question 4

what are the components of the retina

Answer 4

an inner and outer plexiform layer

photoreceptors called rods and cones - rods night vision, cones daylight vision

Question 5

cornea
- vascularity
- layers

Answer 5

avascular - derives its oxygen from the tear film and aqueous humour

consists of 5 layers
collagen fibres regularly arranged

Question 6

where does the optic nerve enter the orbit

Answer 6

through the optic foramen

Question 7

where does the ophthalmic artery arise from

Answer 7

the carotid artery and supplies the retina

Question 8

three Cs of the optic disc

Answer 8

Cup - pale centre devoid of neuroretinal tissue. estimate cup to disc ratio. 1/3 considered normal. increased ratio=less neuroretinal tissue –> glaucoma

Colour - orange-pink donut with a pale centre.

Contour - should be clear and well defined. if swollen may indicate papilloedema

Question 9

how are pupils best dilated for fundoscopy

when not to use

Answer 9

1% tropicamide eye drops - short acting dilation
can also use Cyclopentolate 1%
Phenylephrine 2.5%

don’t use if any symptoms of acute angle closure glaucoma such as a painful sore red eye

Question 10

dry age related macular degeneration

presentation
risk factors
O/E
treatment

Answer 10

gradual loss of central vision (as the macular region is responsible for this area of fine vision).

difficulty with reading and seeing fine detail, and often cannot see people’s faces clearly.
lines can appear distorted

Risk factors include female gender, smoking, hypertension and previous cataract surgery. Peripheral vision is spared.

O/E
visual acuity affected
fundoscopy; optic disc normal, peripheral retina flat, hard to visualise macula with drusen (lipid deposits) usually seen

No treatment currently available
some evidence that high doses of vitamins A, C, E and copper and zinc may slow disease progression

Question 11

what are the signs and symptoms of glaucomatous optic neuropathy

Answer 11

raised intraocular pressure, optic nerve damage (cupping) and peripheral visual field defect (visual acuity usually preserved)

Question 12

what is glaucoma

Answer 12

a condition where the optic nerve becomes damaged
usually caused by fluid building up in the front part of the eye, which increases pressure inside the eye. Glaucoma can lead to loss of vision if it’s not diagnosed and treated early.

Question 13

glaucoma risk factors

Answer 13

race
old age
family history
short sightedness
diabetes
having a thin cornea
wearing tight tie and collar

Question 14

normal pressure in the eye

how is it measured

Answer 14

10-20mmHg
<5 too low
>22 too high

measured with a Goldmann tanometer

Question 15

where does aqueous humour drain out of the eye

Answer 15

the canal of schlemm
if blocked can raise pressure in the eye

Question 16

which medications can lower intraocular pressure (used in AACG)

Answer 16

betablockers
pilocarpine
prostaglandin analogues
carbonic anhydrase inhibitors

Question 17

what is wet macular degeneration

Answer 17

fluid and/or blood develops in the retina due to neovascularisation which occurs in an attempt to restore function

can present suddenly with loss of central vision and distortion and requires an urgent referral as treatments exist (e.g., intra-vitreal anti VEG-F injections)

Question 18

risk factors for acute angle closure glaucoma

Answer 18

female
near sighted (hypermetropia)
dilatation of pupil
lens growth associated with age

Question 19

symptoms of acute angle closure glaucoma

Answer 19

vomiting
progressive subacute headache
blurred vision

Question 20

signs of acute angle closure glaucoma

Answer 20

red eye
dilated pupil
cloudy cornea
blue iris

Question 21

what happens to the intraocular pressure in acute angle closure glaucoma

Answer 21

quickly rises to >50mmHg

Question 22

management of acute angle closure glaucoma

Answer 22

peripheral idiotomy to restore the flow of aqueous humour

medical management to reduce pressure

same procedure in other eye prophylactically

follow up in glaucoma clinic to assess visual fields

Question 23

how does central retinal artery occlusion present

Answer 23

sudden, painless loss of vision - can be reduced to NPL - ophthalmic emergency

cherry red spot on fundoscopy

Question 24

what other condition must be excluded in a central retinal artery occlusion

Answer 24

giant cell (temporal) arteritis

(only in a few patients)

Question 25

what causes central retinal artery occlusion in most patients

Answer 25

non-inflammatory vascular problems associated with raised cholesterol, hypertension and atherosclerosis need good personal Hx and FHx of diabetes, hypertension and hypercholesterolaemia as well as other vascular problems and vascular risk factors

Question 26

retinal detachment: - presentation - risk factors - management

Answer 26

sudden onset of floaters or flashes in vision preceding loss of vision myopia, trauma, advancing age needs surgery immediately - retina is usually flattened with gas or oil, after having the vitreous removed urgency and prognosis (retaining vision) depends on whether macular is detached

Question 27

orbital cellulitis - presentation - common pathogens

Answer 27

periocular erythema, swelling and pain reduced eye movements and vision fever unwell life threatening ophthalmic emergency often associated with a respiratory tract infection and involves common pathogens such as Haemophilus influenzae Staphylococcus aureus Streptococcus pneumoniae Betahaemolytic streptococcu

Question 28

orbital cellulitis - investigations - management

Answer 28

orbital scan (MRI or CT) FBC swab from conjuctivae blood cultures IV antibiotics according to cultures and swabs hourly observations including visual acuity

Question 29

infective endophthalmitis

Answer 29

rare ocular emergency presenting with red eye, pain, reduced vision signs; pus in anterior chamber and injected conjunctiva can be associated with recent surgery and with recent ocular surgery refer urgently to ophthalmology

Question 30

signs of conjunctivitis

Answer 30

injected conjunctiva normal visual acuity mucoid discharge reactive pupils

Question 31

investigations in conjunctivitis

Answer 31

bacterial swabs viral swabs chalmydia swabs

Question 32

what can be used to investigate the cornea in a presentation of red eye

Answer 32

Fluorescein (sodium fluorescein) - an orange water-soluble dye. Used intravenously or topically. Visualized using a cobalt-blue filter which causes the dye to fluoresce a bright green color. Fluorescein does not stain intact corneal epithelium but does stain the deeper corneal stroma, highlighting the area of the epithelial loss.

Question 33

how can herpes simplex infection affect the eye

Answer 33

dendritic ulcers of the eye are associated with herpes simplex Most primary infections are subclinical or cause only mild fever, malaise and upper respiratory tract symptoms. Blepharitis and follicular conjunctivitis may develop but are usually mild and self-limited. Treatment, if necessary, involves topical aciclovir ointment for the eye and/or cream for skin lesions

Question 34

what is anterior uveitis how does it present what clinical signs

Answer 34

inflammation of the uveal tract which involves the iris, ciliary body, retina and choroid usually red, aching eyes, vision can be blurred no discharge refer to ophthalmology signs of intra-ocular inflammation, such as cells in the anterior chamber and posterior synechiae. if posterior synechiae (where iris sticks to lens) irregular pupil and raised intraocular pressure can occur often associated with autoimmune conditions

Question 35

treatment and management of bacterial conjunctivitis

Answer 35

send off swabs for PCR chloramphenicol eye drops cool compresses avoid contact lenses for duration of treatment and 48hrs afterwards irrigation of the eye may be useful in purulent cases

Question 36

what are the common bacterial and viral causes of conjunctivitis

Answer 36

bacterial: S. pneumoniae, S. aureus, H. influenzae and Moraxella catarrhalis. occasional gonnhorhea or chlamydia can viral: commonly adenoviruses - self limiting

Question 37

what is bacterial keratitis what can it progress to management

Answer 37

infection of the cornea, usually presenting with an ulcer (pain and redness). more common in contact lense wearers can progress rapidly to cause a hypopyon, which represents pus in the anterior chamber this can cause a corneal perforation refer urgently to ophthalmology stop contact lens wear don't prescribe steroid eye drops treated with frequent topical antibiotics

Question 38

when do 6th nerve palsies tend to occur

Answer 38

tend to be acquired later in life due to other conditions that can damage the nerve such as vascular factors reducing blood supply to the nerves (microvascular palsy) - these can resolve spontaneously direct pressure on the nerve such as from a tumour or raised intracranial pressure can also cause a lateral rectus palsy

Question 39

features of a 6th nerve palsy

Answer 39

double vision (horizontal) inability to abduct the eye convergent squint

Question 40

what does a third nerve palsy that includes a dilated pupil indicate

Answer 40

that there is mass effect on the nerve ie. an aneurysm or other SOL- neuroimaging required urgently this is also often associated with pain can also have vascular causes - less urgent

Question 41

signs of a third nerve palsy

Answer 41

horizontal and vertical diplopia eye is down and out pupil may be dilated ptosis

Question 42

management of an orbital floor fracture

Answer 42

urgent maxillofacial surgery broad spectrum antibiotic advise patient not to blow their nose

Question 43

signs of an orbital floor fracture

Answer 43

double vision on upward gaze infra-orbital parasthesia

Question 44

4th nerve palsy presentation

Answer 44

affected eye turns up and out in the forward position when looking laterally to affected side eye up more 4th nerve innervates superior oblique which moves eye down and in

Question 45

what main condition other than a CN palsy can cause diplopia

Answer 45

myasthenia gravis - fatiguing of oculomotor muscles may present with diplopia and ptosis

Question 46

DVLA double vision

Answer 46

patient must stop driving immediately and inform the DVLA Patients can return to driving after a period of adaptation or if the double vision has resolved. Patients can hold a Group 1 license (cars/personal vehicles) if their double vision is controlled with prisms or if they occlude (patch) one eye. The other eye however must have sufficient vision (6/12) and adequate visual field. Drivers of HGV eg lorries, buses (who require a Group 2 license) cannot drive with persistent diplopia (even after period of adaptation) or patched.

Question 47

management options for diplopia

Answer 47

All patients should be referred to an orthoptist options: - patching eye - temporary fresnel prism, can be fitted and the power adjusted as the palsy resolves - if long-lasting then permanent prisms can be fitted to glasses - surgical intervention can be considered to realign the eyes

Question 48

what complication of otitis can cause diplopia

Answer 48

a cavernous sinus thrombosis - headaches and diplopia needs to be urgently excluded

Question 49

what is anisocoria

Answer 49

unequal pupil size

Question 50

what is leukocoria causes in children

Answer 50

white pupil - red reflex lost - opacity in the optical media of the eye Congenital cataract Retinoblastoma Coat's disease Intraocular infection

Question 51

what cause of leukocoria needs to be excluded urgently in children what does the retina look like

Answer 51

retinoblastoma raised white mass on the retina

Question 52

what dilating drops are used in children

Answer 52

Cyclopentolate

Question 53

what is Retinopathy of prematurity (ROP)

Answer 53

proliferative retinopathy affecting premature infants of very low birth weight, who have often been exposed to high ambient oxygen concentrations

Question 54

screening for retinopathy of prematurity

Answer 54

Babies born at or before 31 weeks gestational age, or weighing 1500 g or less, should be screened for ROP at around 4–7 weeks postnatally. Only about 8% of babies screened actually require treatment.

Question 55

treatment for retinopathy of prematurity

Answer 55

Laser photocoagulation is the treatment of choice, and it is successful in around 80% of cases if left untreated can progress to sight threatening complications such as vitreous haemorrhage and retinal detachment

Question 56

what is retinoblastoma types management spread

Answer 56

intraocular malignancy of childhood <3 years - malignant transformation of primitive retinal cells before differentiation heritable (40% cases, gene on chromosome 13) or non-heritable (60% of cases, unilateral)\ complex treatment depending on how advanced and on vision: combination of chemotherapy, radiotherapy, brachytherapy and enucleation (removing the eyeball) metastasis can occur especially if optic nerve invasion, massive choroidal invasion, anterior chamber involvement and orbital spread

Question 57

congenital cataracts

Answer 57

present with leukocoria in children (3 in 10000 live births) 2/3 bilateral and more likely to be caused by genetic mutation, chromosomal abnormalities, metabolic disorders and intrauterine infections unilateral more likely to be sporadic

Question 58

surgery in congenital cataracts

Answer 58

complex surgeries carried out depending on timing, density and unilateral/bilateral bilateral dense cataracts - operate at 4-6 weeks to prevent amblyopia bilateral partial - may not require surgery but done later if so unilateral dense cataract urgent surgery usually within days and aggressive anti-amblyopia therapy (often poor result)

Question 59

production and flow of aqueous humour

Answer 59

produced by the ciliary body flows from the ciliary body, around the lens and under the iris, through the anterior chamber, through the trabecular meshwork and into the canal of Schlemm

Question 60

visual changes in glaucoma

Answer 60

peripheral vision impaired

Question 61

what medications can precipitate an acute angle closure glaucoma

Answer 61

Adrenergic medications such as noradrenalin Anticholinergic medications such as oxybutynin and solifenacin Tricyclic antidepressants such as amitriptyline

Question 62

pathophysiology in diabetic retinopathy

Answer 62

Hyperglycaemia damages small blood vessels - increased permeability leads to blot haemorrhages and hard exudates Micro aneurysms Venous beading Damage to nerve fibres - cotton wool spots Intraretinal microvascular abnormalities Neovascularisation - can cause diabetic macular oedema

Question 63

types of diabetic retinopathy

Answer 63

proliferative retinopathy (neovascularisation) non-proliferative retinopathy maculopathy (macular oedema and ischaemic maculopathy)

Question 64

complications of diabetic retinopathy

Answer 64

Retinal detachment Vitreous haemorrhage (bleeding in to the vitreous humour) Rebeosis iridis (new blood vessel formation in the iris) Optic neuropathy Cataracts

Question 65

management of diabetic retinopathy

Answer 65

Laser photocoagulation Anti-VEGF medications Vitreoretinal surgery (keyhole surgery on the eye) may be required in severe disease

Question 66

what is a cataract what are the symptoms

Answer 66

a cataract is where the lens becomes progressively opacified Very slow reduction in vision Progressive blurring of vision Change of colour of vision with colours becoming more brown or yellow “Starbursts” can appear around lights, particularly at night time loss of red reflex O/E

Question 67

symptoms of vitreous haemorrhage

Answer 67

Painless Spots of vision loss Floaters Flashing lights

Question 68

retinal detachment - symptoms - management

Answer 68

Peripheral vision loss - often sudden and like a shadow coming across the vision Blurred or distorted vision Flashes and floaters Ophthalmological emergency - needs urgent assessment if suspected Management of retinal detachment aims to reattach the retina and reduce any traction or pressure that may cause it to detach again. needs to also be done to any tears to prevent detachment

Question 69

retinal vein occlusion presentation treatment

Answer 69

thrombus forms in the retinal veins and blocks the drainage of blood from the retina - build up leads to oedema and retinal haemorrhages which damage the retina and cause loss of vision presents; sudden painless loss of vision treatment; laser coagulation, intravitreal steroids, antiVEGF therapies

Question 70

subconjunctival haemorrhage

Answer 70

small blood vessel rupture within the conjunctiva causing bleeding between the conjunctiva and sclera causes bright red bleeding across the eye can be caused by trauma or straining spontaneously resolve - check about anticoagulants

Question 71

what is amblyopia what are the main causes can it be treated

Answer 71

reduced visual acuity due to a problem focusing in early childhood most commonly due to a strabismus (lazy eye) - treated with patch or dilating drops of good eye for 4-6 hrs a day other causes include refractive error and congenital cataracts can only be treated if detected early enough when the neurological plasticity is still present

Question 72

what condition is giant cell arteritis strongly associated with

Answer 72

polymyalgia rheumatica

Question 73

management of suspected GCA

Answer 73

start oral prednisolone 40-60mg a day refer urgently to ophthalmology for temporal artery biopsy if visual loss IV methylprednisolone

Question 74

what is typically the defect causing fluid in a chronic open angle glaucoma

Answer 74

defect in the trabecular meshwork which slows down the flow of aqueous humour

Question 75

papilloedema on fundoscopy

Answer 75

venous engorgement, blurring of optic disc margin, Loss of optic cup and loss of venous pulsation

Question 76

differentiating between scleritis and episcleritis

Answer 76

scleritis is painful whereas episcleritis is not

Question 77

Horners syndorme

Answer 77

miosis + ptosis + enophthalmos +/- anhydrosis (loss of sweating on one side)

Question 78

orbital cellulitis needs... periorbital cellulitis

Answer 78

IV antibiotics, admission and regular observations oral antibiotics usually sufficient

Question 79

screening in those with a FHx of glaucoma

Answer 79

annual screening from age 40

Question 80

how can the orbit be decompressed

Answer 80

lateral canthotomy

Question 81

management of anterior uveitis

Answer 81

urgent ophthalmologist review pupil dilatation steroid eye drops

Question 82

proliferative diabetic retinopathy should be

Answer 82

referred urgently to hospital