Opthalmology Flashcards
accomodation
ability of the lens to change shape and vary the amount it refracts light
presbyopia
diminishing ability of the lens to accommodate - usually occurs with increasing age
Cataract
any opacity of the lens
Phacoemulsification
Surgery for cataracts where the lens is removed and replaced via a small self-sealing incision in the cornea
myadrisis
pupil dilation to allow more light to enter the eye - sympathetic innervation of dilator pupillae (arranged radially)
miosis
pupil contraction to allow less light to enter the eye - parasympathetic innervation (carried by oculomotor) of sphincter pupillae (encircles the pupillary margin)
anterior uveitis
inflammation of the iris +/- the ciliary body
intermediate uveitis
inflammation of the posterior ciliary body and nearby peripheral retina and choroid
posterior uveitis
inflammation of the retina and choroid
panuveitis
inflammation of the entire uveal tract (iris, ciliary body and choroid,
cycoplegia
paralysis of the ciliary muscle
rod cells
cells in the neural retina which detect contrast and movement
cone cells
cells in the neural retina which detect colour and detail
heterophoria
misalignment of the eyes
heterotropia
constant misalignment of the eyes
latent strabismus
misalignment of the eyes when vision is dissociated - cover/uncover test
ambylopia
‘lazy eye’ - inability to achieve full visual acuity despite corrected refractive error. Due to eye and brain failing to communicate
diplopia
double vision
incomitant strabismus
angle of deviation changes with direction of gaze
concomitant strabismus
angle of deviation remains the same with all directions of gaze
agnosia
inability to recognise common objects despite an intact visual apparatus
amaurosis fugax
transient, painless loss of vision
amblyopia
reduced visual acuity with no demonstrable organ defect
anopthalmos
congenital absence of the eyeball
blepharitis
inflammation of the eyelid
chemosis
conjunctival swelling
colobloma
congenital cleft due to failure of some portion of the eye or eyelid to complete growth
cycloplegic
a drug which paralyses accommodation and dilates the pupil
dacrocystitis
infection of the lacrimal sac
ectropion
turning out of the eyelid
entropion
turning inwards of the eyelid
enucleation
complete surgical removal of the eyeball
hypermetropia
long-sightedness (close objects are blurred)
myopia
short-sightedness (commonly due to elongated eyeball ) distant objects are blurred.
astigmatism
refractive error which due to cornea having greater curvature in one plane compared to another i.e. rugby ball shaped rather than football shaped.
nystagmus
rapid, involuntary movements of the eye ball in any direction
ptosis
drooping of the eyelid
exophthalmos
abnormal protrusion of the eyeball
RAPD causes
extensive retinal detachment
optic neuritis
Cover/uncover test, which eye is the fixating eye?
movement will only be seen when covering the fixating eye
Differentiating episcleritis and scleritis
In episcleritis, the injected vessels are mobile when gentle pressure is applied on the sclera. In scleritis, vessels are deeper, hence do not move
Features of herpes zoster opthalmicus
vesicular rash around the eye, which may or may not involve the actual eye itself
Hutchinson’s sign: rash on the tip or side of the nose. Indicates nasociliary involvement and is a strong risk factor for ocular involvement
Manegement of herpes zoster opthalmicus
oral antiviral treatment for 7-10 days
ideally started within 72 hours
intravenous antivirals may be given for very severe infection or if the patient is immunocompromised
ocular involvement requires urgent ophthalmology review
Retinal Changes in diabetic retinopathy
Mild - 1 or more microaneurysm
Moderate - microaneurysms, blot haemorrhages, hard exudates, cotton wool spot
Severe - blot haemorrhages and microaneurysms in 4 quadrants, venous beading in at least 2 quadrants, intraretinal microvascular abnormalities
Proliferative - retinal neovascularisation - may lead to vitreous haemorrhage, fibrous tissue forming anterior to retinal disc
ARMD
types and causes
degeneration of photoreceptors
dry - formation of drusen
wet - choroidal neovascularisation leads to blood and serous fluid leakage
(4) ARMD risk factors
increasing age
smoking
family Hx
CVS risk factors
Presentation of ARMD (5)
subacute loss of vision difficulty seeing in the dark variable vision day to day flashing/flickering lights 'glare' around objects.
Mx of ARMD
dry - antioxidants
wet - anti-VEGF, laser photocoagulation
Causes of cataracts (9)
increasing age smoking alcohol diabetes corticosteroid use trauma radiation exposure myotonic dystrophy hypocalcemia
Presentation of cataracts(5)
gradual onset decrease in VA faded colours glare halos around lights
Mx of cataracts
optimise vision - glasses and increased lighting
surgery - replace the lens with an artificial one
compliciations of phacoemulsification
posterior capsule opacification
posterior capsule rupture
retinal detachment
inflammation of the aqueous or vitreous humour
Retinal detachment presentation
Dense shadow that starts peripherally progresses towards the central vision
A veil or curtain over the field of vision
Straight lines appear curved
Central visual loss
Vitreous haemorrhage presentation
Large bleeds cause sudden visual loss
Moderate bleeds may be described as numerous dark spots
Small bleeds may cause floaters
Argyll-Robertson Pupil
a pupil that accommodates but does not react to light
seen in neurosyphilis and diabetes
causes of mydriasis (4 plus 3 drug groups)
third nerve palsy Holmes-Adie pupil traumatic iridoplegia phaeochromocytoma congenital
Drugs:
topical mydriatics: tropicamide, atropine
sympathomimetic drugs: amphetamines, cocaine
anticholinergic drugs: tricyclic antidepressants
What is a Holmes-Adie pupil?
A benign condition most commonly seen in women.
usually a unilateral dilated pupil
once the pupil has constricted it remains small for an abnormally long time
slowly reactive to accommodation but very poorly (if at all) to light
Causes of papilloedema (5)
space-occupying lesion: neoplastic, vascular malignant hypertension idiopathic intracranial hypertension hydrocephalus hypercapnia
What is acute closed-angle glaucoma?
physical obstruction of aqueous flow through the trabecular network resulting in a sudden onset raised intraocular pressure, causing optic neuropathy
what is chronic open-angle glaucoma?
increased resistance in the trabecular network results in increased IOP which causes optic neuropathy
presentation on acute closed-angle glaucoma (7)
acutely painful eye or headache
decreased visual acuity
pain exacerbated by mydriasis - dark room
red eye
seeing haloes around lights
corneal oedema
systemic upset e.g. nausea, vomiting, abdo pain
risk factors for acute closed-angle glaucoma (3)
increasing age
pupillary dilatation
hypermetropia
management of acute closed-angle glaucoma
urgent Opthalmology referral
reduce aqueous secretions - acetazolamide
constrict pupil - pilocarpine eye drops
risk factors or chronic open-angle glaucoma (7)
increasing age family hx being black myopia hypertension diabetes corticosteroids
presentation of chronic open-angle glaucoma (3)
insidious - often detected at routine appointments
decreased peripheral vision, initially nasal scotoma
decreased VA
fundoscopy findings in chronic open-angle glaucoma(5)
optic disk cupping (cup:disk ration >0.7) optic disk pallor bayonetting of vessels cup notching disk haemorrhage
management of chronic open-angle glaucoma
1st - prostaglandin analogue eyedrops
2nd - beta-blocker eye drops
3rd surgery or laser therapy
What is Nasolacrimal duct obstruction? management?
imperforate membrane, usually at the lower end of the lacrimal duct causes eye-watering
Around 1 in 10 infants have symptoms at around one month of age
teach parent lacrimal duct massage
risk factors for vitreal haemorrhage (5)
Diabetes Trauma Anticoagulants Coagulation disorders Severe short sightedness
staging of hypertensive retinopathy
I Arteriolar narrowing and tortuosity
Increased light reflex - silver wiring
II Arteriovenous nipping
III Cotton-wool exudates
Flame and blot haemorrhages
IV Papilloedema
