Ophthalmology summary

Question 1

leading cause of blindness in the UK?

Answer 1

AMD

Question 2

leading cause of blindness worldwide?

Answer 2

cataract

responsible for 51% of world blindness according to WHO

Question 3

what are the indications for use of mydriatic and cytoplegic drops?

Answer 3

dilate pupil for retina visualisation
paralyse accommodation in management of children with amblyopia
use in refraction of children for glasses prescription

ACT: atropine-acts for 1-2 weeks
cyclopentolate-acts over a day
tropicamide-acts over 15-20 mins

phenylephrine-sympathetic agonist-acts over 3-6hrs

Question 4

contraindications to mydriatic drops?

Answer 4

untreated narrow angle glaucoma*

Question 5

side effects of mydriatic drops?

Answer 5

eyelid whitening due to vasoconstriction, this will resolve as drops wear off
atropine can cause face redness and a warm sensation to touch, may need a lower dose
all sting the eyes for a few seconds after instillation
blurring effect-pt must be warned not to drive until effect has worn off

Question 6

causes of a RAPD?

Answer 6

optic neuritis
ischaemic optic neuropathy
traumatic optic neuropathy
glaucoma where 1 optic nerve has particularly severe damage
central retinal artery occlusion
central retinal vein occlusion
retinal detachment
severe macular degeneration

Question 7

how is a RAPD examined for?

Answer 7

swinging flash light test**

Question 8

why might the fundus NOT be visible during examination in a patient with acute angle closure glaucoma?

Answer 8

due to corneal oedema

Question 9

management of acute angle closure glaucoma?

Answer 9

must restore normal aq flow
IV 500mg acetazolamide
if this is ineffective then consider oral glycerine (with lemon juice due to nauseating sweetness) or IV mannitol=hyperosmotic agents
topical pilocarpine (parasympathomimetic) to constrict pupil, but only effective once IOP less than 40mmHg due to iris ischaemia, sometimes started prophylactically in other eye
topical beta blockers and steroids to reduce pressure and inflammation respectively
then iridotomy (with laser) or iridectomy (hole in iris made surgically), and tment also in other eye.

Question 10

initial tment of pt with central artery of retina occlusion?

Answer 10

need to reduce pressure via an anterior chamber paracentesis

Question 11

how does getting older affect risk of developing acute angle closure glaucoma?

Answer 11

increased risk as lens continues to grow which reduces depth of anterior chamber

Question 12

what may precipitate an attack of acute angle closure glaucoma?

Answer 12

physiological mydriasis e.g. being in a darkened room

or physiological anterior chamber shallowing when person in prone position e.g. reading a book.

Question 13

what is the concern in relation to eyes of facial nerve palsy?

Answer 13

exposure keratopathy-if unable to close eyelids fully, susceptible to corneal abrasion and ulcers, can be keratitis and may be endophthalmitis and permanent visual loss.

*unable to close eyelids fully-lagophthalmos

Question 14

what must we examine if a patient has a facial nerve palsy?

Answer 14

eyes: can they close their eyelids fully?, check for Bell’s phenomenon, check corneal sensation and then cranial nerve examination.
Bell’s phenomenon-when the pt is asked to close their eyes, if eyelids cannot close fully we should see the eye move upwards and outwards so that it is protected.

Question 15

abducens nerve palsy tment?

Answer 15

should be spontaneous improvement
treat in relation to cause e.g. HTN or DM-ensure good control
can use prisms to help reduce diplopia, and in severe cases can patch 1 eye
may consider surgery 6-12mnths after onset when all spontaneous improvement been achieved and condition stable.

Question 16

what blood test should be performed in pt over 55yrs of age presenting with 6th nerve palsy?

Answer 16

ESR-to rule out GCA

Question 17

a 20 yr old pt presents with 6th nerve palsy and no hx of preceding trauma, what investigation should be performed?

Answer 17

MRI-?look for MS, or cause of raised IC pressure e.g. SOL

must also MRI if bilateral presentation-look for cause of raised ICP

Question 18

if MRI is normal in presentation of bilateral 6th nerve palsy, what investigation might be required?

Answer 18

lumbar puncture to exclude benign intracranial HTN

Question 19

pathologies that may affect optic chiasm?

Answer 19

neoplastic: pituitary adenoma, meningioma, craniopharyngioma, NP carcinoma, glioma, mets
non-neoplastic masses: rathke’s pouch cyst, aneurysms, sphenoidal sinus mucocele
other: demyelination, inflammation, trauma, vasculitis, pituitary abscess

Question 20

why should visual field testing be carried out in patients with non specific headaches or endocrine disturbance?

Answer 20

look for features indicative of a pituitary adenoma e.g. bitemporal hemianopia, as visual symptoms tend to occur gradually.

Question 21

visual symptoms of a pituitary adenoma?

Answer 21

bitemporal hemianopia
colour desaturation
optic atrophy
diplopia
see-saw nystagmus

Question 22

define herpes zoster ophthalmicus, and how does it present?

Answer 22

reactivation of VZV in area supplied by ophthalmic division of trigeminal nerve
vesicular rash around the eye
hutchinson’s sign-rash on tip of side of nose-nasociliary involvment-high likelihood of ophthalmic involvement

Question 23

management of herpes zoster ophthalmicus?

Answer 23

ocular involvement requires urgent ophthalmology r/v
ORAL antiviral treatment-aciclovir, for 7-10 days, aciclovir 5 times a day
PO steroids-may reduce duration of pain, but no effect on development of post herpetic neuralgia

Question 24

complications of herpes zoster ophthalmicus?

Answer 24

ocular-keratitis, anterior uveitis, episcleritis, conjunctivitis
post herpatic neuralgia
ptosis

Question 25

what is an argyll-robertson pupil?

Answer 25

pupil which accomodates but does not constrict to light
so o/e=small, irregular pupils
sometimes seen in neurosyphilis (late symptomatic disease with treponema pallidum), can also be caused by DM

Question 26

what is a holmes-adie pupil?

Answer 26

neurological disorder where pupil is large and irregular, accomodates but constricts slowly and incompletely to light.
once constricted remains small for an abnormally long time (tonic pupil)
considered a variant of normal, but rarely result of a lesion in parasympathetic efferent pathway
associated with absent deep tendon reflexes=holmes-adie syndrome.
hypersensitivity to G pilocarpine solution.

Question 27

1st line medical treatment for primary open angle glaucoma and ocular HTN?

Answer 27

topical PG analogue or prostamide e.g. latanoprost.

or a topical beta blocker

Question 28

what is used to precisely delineate the visual fields?

Answer 28

a perimeter

Question 29

what PMH would we like to know in presentation of a visual complaint?

Answer 29

DM
HTN
thyroid disease
AI conditions
arthritis
AS

Question 30

give 5 ways of testing optic nerve function?

Answer 30

test visual acuity-Snellen
visual fields-hatpin-testing by confrontation with red hatpin
pupil response to light-direct and consensual
colour vision
fundoscopy

Question 31

how can pinhole use be helpful when testing visual acuity?

Answer 31

may improve a patient’s visual acuity by focusing light on to the retina e.g. a patient with cataracts, or an uncorrected refractive error.
if visual acuity is worsened by use of pinhole, then likely a maculopathy (macula-fovea centralis-area of most acute vision with highest concentration of cone cells) e.g. diabetic maculopathy or AMD.

Question 32

how can visual acuity be tested?

Answer 32

Snellen chart
can try and improve acuity with pinhole
fingers
hand movements
light

Question 33

what is blepharospasm?

Answer 33

uncontrollable and painful muscle contractions around the eye
can give botulinum injection, but must start low as can cause diplopia, facial drooping and eyelid closure.

Question 34

where is damage located to cause an RAPD?

Answer 34

between the optic nerve and optic chiasm

Question 35

patient presents with a severe headache and sudden onset left eye ptosis, with a down and out eye and pupil dilation o/e, what is the likely diagnosis and appropriate management?

Answer 35

posterior communicating artery aneurysm causing a painful 3rd nerve palsy, with compression of PNS fibres running on the outside of the nerve-causes pupil dilation.
artery=connects the posterior cerebral artery with the ICA
require urgent neurosurgical r/v
investigation-MR angiogram, and possibly angiography
would also check BP and blood glucose.

Question 36

presenting features of posterior vitreous detachment?

Answer 36

sudden onset floaters and photopsia=result of traction of detached vitreous gel on the retina.
o/e: vitreous opacities

laser applied around the tear can prevent retinal detachment.

Question 37

investigation and management of a bacterial corneal ulcer e.g. in someone that wears contact lenses?

Answer 37

immediate r/f to eye casualty
scrape ulcer for culture, and also the contact lens and and any lens containers
topical BS antibiotics given as an inpatient whilst awaiting results from microbiology.

Question 38

most common cause of persistent epiphora (watery eye) in an infant?

Answer 38

imperforate nasolacrimal duct
should reassure parents
advise regular massaging of lacrimal sac
if persistence after 1 year old, then may r/f to ophthalmologist for syringing and probing of nasolacrimal duct-drains tears from eye into the inferior meatus of the nasal cavity.

Question 39

what diagnosis do we worry about if a pt with a corneal graft presents around a year later with a red eye and blurred vision?

Answer 39

graft rejection

if this is confirmed will need intensive topical steroid treatment to save the graft.

Question 40

diagnosis of sudden transient visual loss in 1 eye, described as a curtain coming down over the vision?

Answer 40

amaurosis fugax-result of blood clot or plaque becoming temporarily lodged in artery of the retinal circulation
may be due to atherosclerosis of carotid artery or ophthalmic artery, cardiac embolus, GCA, SLE, antiphospholipid syndrome, temporary vasospasm.

Question 41

what would the development of tunnel vision in a young patient with a FH of early blindness suggest?

Answer 41

retinitis pigmentosa

Question 42

what do we need to measure to know the implant power required for a new lens in cataract surgery?

Answer 42

the corneal curvature and the length of the eye
cornea responsible for most light refraction
curvature measured with a keratometer
shorter eye-more powerful lens required to focus light on the retina, measured with A scan mode of ultrasound.

Question 43

what are the 2 different blood supplies to the retina?

Answer 43

inner retina-bipolar cells, ganglion cells, nerve fibre layer=central artery of retina from ophthalmic from ICA
outer retina-photoreceptor cells and RPE=choroid.

Question 44

why should anti-VEGF not be given to a wet AMD patient who has had a recent stroke?

Answer 44

VEGF may be needed to help improve the circulation

Question 45

what is suggested by loss of vision for a few seconds when standing from sitting?

Answer 45

raised ICP

Question 46

what is indicated by presence of white spots at the optic disc in presentation of a pt with severe headache, temporal artery tenderness and jaw claudication?

Answer 46

ischaemic optic neuropathy that has occurred due to GCA