Opthalmology Flashcards
what does this image show
Cataract on slit lamp examination
What is a cataract?
a very common cause of gradual visual loss caused by the opacification of the crystaline lens
what are the causes of cataracts?
- Ageing
- trauma
- metabolic disorders eg galacosemia
- medications
- congenital problems
what medications cause cataracts?
PC SAAD
- corticosteroids
- allopurinol
- aspirin
- chloroquine
- diuretics
- phenothiazines
- simvastatin
What is the main presentation of cataract?
Gradual visual loss
visual acuity depends on the type of cataract
what are the types of cataracts?
- Cortical
- subcapular
- Star flower
- congenital
- nuclear
describes the typical symptoms of a cortical cataract?
Good visual acuity
may complain of halos around lights and glare
can cause double vision or fractured vision
describe the symptoms of a subcapsular cataract?
Good vision in dim lighting on dilation
worse in bright lights
describe the cause of a star flower cataract?
Trauma
describe a nuclear cataract presrentation?
the most common type of cataract
associated with increased ageing
causes blurred vision and washed out colours
on examination of the patient who presents with :
- gradual decreased visual acuity
you find there is:
- diminished red light reflects
- normal fundus and optic nerve reduced visual acuity
slit lamp examination shows:
- a cloudy anterior chamber
what is the diagnosis?
cataract
what is the management of a cataract?
Surgical
what are some intraoperative complications of cataract surgery?
Lens capsule rupture
haemorrhage
what are some post-operative complications of cataract surgery?
Lens dislocation
capsule opacification
infection and inflammation / post op endopthalmitis
what does this image show?
small white crystalline drusen
what does this image show?
Larger confluent soft drusen
what does this image show?
Dry macular degeneration
- pigmented epithelium
- choroid and retinal clumping
- geographical atrophy
- drusen
what does this image show?
Wet macular degeneration
- chorodial neurovascular membranse
- sub- retinal haemorrhages and exudates
- localised retinal detachment - which can then cause retinal scarring appearing as a black blob
what is the macula?
where visual acuity is at its highest
Has functioning rods and cones
what is the fovea?
Located at the centre of the macula
there are only cones
this is where there is the best visual acuity
what is macular degeneration?
mainly an age-related condition
causing a gradual visual loss
early stages are associated with normal or near normal vision
later stages have decreased visual acuity and eventual loss of central vision
what are the two types of macular degeneration?
Wet/ dry
describe the pathophysiology behind dry macular degeneration?
There is atrophy of the retina
describe the pathophysiology behind wet macular degeneration?
There is new vessel growth under the retina
what sign do both types of macular degeneration share in the initial stages of the disease process?
drusen
In dry macular degeneration what is the most common presenting complaint?
Central Scotoma (visual loss) with good peripheral vision but which deteriorates
lead to legal blindness – is the most common cause of legal blindness in the UK
what is the management of dry macular degeneration?
Low vision aids
limited evidence for nutritional supplements and antioxidants
what is the most common presenting complaint of wet macular degeneration?
Distorted vision
micropsia leading to central’s scotoma’s
has faster visual loss then with dry macular degeneration
what is the management of wet macular degeneration?
rapid referral treating with injections of anti-TNF beta- macugen
or
laser after IV photosensitive drugs- verteporfin (if under the fovea)
how can you differentiate between wet and dry macular degeneration?
florosine test
What is the angle?
The name given to the space between the posterior surface of the cornea and the interior surface of the iris
it is where the aqueous leaves the eye
what is aqueous?
Nourishing fluid for the lens made by the ciliary body entering through the eepiscleral veins
what range should put the intraocular pressure be?
< 21
What is the pathophysiology of open angle glaucoma?
Dysfunction of the outflow of aqueous humour
due to obstruction in the draining
causes an increase of intraocular pressure
what does this image show?
Glaucoma characterised by :
an increased cup:disc ratio and notching of the optic nerve
A patient present with:
- Halos around lights
- aching brow pain
- headaches nausea and vomiting
- reduced visual acuity
- eye redness
on examination you note:
- elevated intraocular pressure
- corneal oedema
- fixed dilated pupil
what is your diagnosis?
acute or subacute angle closure glaucoma
in more advanced disease what is the presentation of open and glaucoma?
Peripheral visual loss leading to Scotoma
what is the management of open angle glaucoma?
Observation of ocular hypertension with regular checkups
use of :
- topical beta-blockers - timodolol
- prostanoids - latanoprist
- carbonic anhydrases - dorzolamide
- alpha agonists - bromide
in more severe cases:
carbonic anhydrase inhibitors acetalozalamide –> surgery
what is the pathophysiology of angle closure glaucoma?
An urgent but uncommon dramatic symptomatic events
there is closure of the anterior chamber angle
results in elevation of intraocular pressure
usually sudden but can be chronic
what other risk factors associated with angle closure glaucoma?
- Female
- hyperopia
- another eye having it
- shallow peripheral anterior chamber
when is chronic angle glaucoma usually diagnosed?
When still asymptomatic on regular eye checks
When is open angle glaucoma usually detected?
On regular eye checkups as open angle glaucoma is usually asymptomatic until more advanced disease
what investigating is diagnostic for angle closure glaucoma?
gorioscopy
plus checking IOP and visual fields
What is the acute management of angle closure glaucoma?
This is a medical emergency and requires immediate referral
treatment is through decreasing intraocular pressure using:
- PO acetazalamide and iv mannitol
what can be done to prevent angle closure glaucoma from occurring again?
iridotomy
what is optic neuritis?
Inflammation of the optic nerve
what causes optic neuritis?
- idiopathic usually
- MS
- sinus infections
- vericella zoster virus
- syphilis
- sarcoidosis
- lupus
what does this image show?
optic neuritis:
Pale optic disc
inflammation / swelling of the optic disc
what is the presentation of optic neuritis
acute or subacute onset of pain (peri orbital or reticulo bulbar)
- getting worse with movements
loss of vision
visual acuity gets worse after one to 2 weeks
usually there is almost full recovery
colour desaturation
relative afferent pupillary defect
what investigations should you perform in optics neuritis?
MRI of the optic nerves – MS
if the history is suggestive of other causes then investigate those:
- serum ACE- increased in sarcoidosis
- ana - positive in SLE
- VDRL - positive in syphilis
- PCR for varicella
how do you treat optic neuritis?
Steroids speed recovery - PO prednisolone
but it does not improve outcomes
if optic neuritis occurs repeatedly or for a prolonged period of time what can happen to the optic nerve?
atrophy and become pale
how can toxoplasmosis causes secondary optic neuritis?
there is an area of neuro retinitis close to the optic nerve
causing it to become swollen
how do you treat secondary optic neuritis to toxoplasmosis?
Steroid and antibiotics
what does this image show?
- Micro aneurysms and cotton wool spots
- intra retinal haemorrhages
- lipid exudates and macular haemorrhages
- macular oedema can occur
Diabetic retinopathy
what are the two types of diabetic retinopathy?
non-proliferative
proliferative
described non-proliferative diabetic retinopathy
It is the early stages of the disease and is less severe
blood vessels become leaky and fluid leaks into the retina
causing blurred vision
describe proliferative diabetic retinopathy
New blood vessels grow which are fragile
these can haemorrhage really quickly
this can cause vision loss and scarring
what is the pathophysiology of diabetic retinopathy?
There is progressive diabetic microvascular leakage and occlusions
With then progressive proliferation of vessels
what is the presentation of diabetic retinopathy?
Floaters
blurred vision
vision loss
when is diabetic retinopathy usually diagnosed?
In the early stages of disease through diabetic eye screening
what should you do if you suspect macular oedema in diabetic retinopathy or otherwise?
order optical coherence tomography
what is diabetic maculopathy?
Diabetic maculopathy is a condition that can result from retinopathy
Maculopathy is damage to the macula - the part of the eye which provides us with our central vision
what should you do if you suspect diabetic maculopathy?
Order fluorescein angiography
laser treatment
what does a fluorescent angiography show?
shows blood vessels and capillary non-perfusion
plus shows the formation of new vessels and haemorrhages
what investigation is required if you suspect retinal detachment?
Beta scan occular ultrasound
a non invasive tool for diagnosing lesions of the posterior segment of the eyebal
what is the management of diabetic retinopathy?
diabetic control
injections of anti-vascular endothelial growth factor
laser
surgery
What does this image show?
retinal artery occlusion of the central artery
- thin retinal arteries
- retinal oedema and pallor
- optic disc becomes pale after months
- you see a cherry red spot
what does this image show?
Retinal artery occlusion of a branch artery
- retinal pallor following the branch of the artery thats occluded
- narrowing of the artery after the embolus
what causes retinal artery occlusion?
Embolus or atherosclerosis from the carotid artery
- reaching the ophthalmic artery or a branch of it in the eye
what is the presentation of retinal artery occlusion?
Sudden almost total loss of vision- central occlusion
if visual field loss – branch occlusion
what is the relevant afferent pupillary defect like in retinal artery occlusion?
relevant afferents pupillary defect is usually still present
What investigations should you perform in retinal artery occlusion?
Usually diagnosis is just through the fundoscopy
a carotid Doppler can be used to aid diagnosis
what is the management of retinal artery occlusion?
Urgent referral with therapeutic intervention in 4-6 6 hours
what is transient monocular visual loss a symptom of?
It is a symptom of TIA
what is a presentation of transient monocular visual loss?
Describe as a curtain coming over vision
lasting around 30 minutes
full recovery after
what does this image show?
Flame haemorrhages due to the inability to drain blood
- if it is localised it indicates a branch occlusion
- widespread indicating that central occlusion
what is retinal vein occlusion?
An interruption of normal venous drainage from the retinal tissue
causing symptoms of acute visual loss
it can be central or one of its branches
what is the presentation of retinal vein occlusion?
Painless sudden vision loss - central
blurring of vision and field defects- branch
almost always unilateral
what risk factors are associated with retinal vein occlusion?
- Hypertension
- diabetes
- atherosclerosis
- glaucoma
- increased age
how do you confirm the diagnosis of retinal vein occlusion?
Fluorescein angiography
how do you manage retinal vein occlusion?
injections of anti tVEGF
- such as rabibizumab or bevacizumab
what proportion of patients with retinal vein occlusion will develop ischaemia?
1/3
how does central retinal vein occlusion with ischaemia differ from vein occlusion without ischaemia on funduscopy?
There isn’t much haemorrhage in CRVO with ischaemia
and you would see:
- swelling of the optic disc
- with cotton wool spots
what is a complication of central retinal vein occlusion with ischaemia?
Neovascularisation requiring laser treatment
What does this image show?
anterior ischaemic optic neuropathy
Looks very similar to vein occlusion but just occurring much closer to the optic disc and nowhere else
near the optic disc you would find:
- flame haemorrhages
- some cotton wool spots
what is anterior ischaemic optic neuropathy?
Interruption of the blood flow to the front of the optic nerve
causing loss of vision as visual information is not passed on to the brain
can be arteric or non arteric
what is the most common cause of arteric anterior ischaemic optic neuropathy?
giant cell arteritis
what are the most common causes of non arteric anterior ischaemic optic neuropathy?
- drop in blood pressure
- increased intraocular pressure
- narrowed arteries/ viscous blood
- vasculitis
which is most common arteric or non arteric (ischemic optic neuropathy)?
non arteric
if you suspect that anterior ischaemic optic neuropathy has been caused by giant cell arteritis what should you do?
- then give immediate high-dose corticosteroids (pred) and reffer for same day assessment by rheumatologist/opthalmologist for eye involvement
- Perform urgent blood tests of ESR CRP and FBC
- temporal artery biopsy is then required to confirm (usually)
what is the presentation of anterior ischaemic optic neuropathy?
sudden painless loss or blurring of vision usually most noticeable after waking from sleep
wost after about two weeks
what is the afferent pupillary reflexes like in anterior ischaemic optic neuropathy?
always present
what is the management of anterior ischemic optic neuropathy?
corticosteroids or anti VEGF (but not much evidence)
a patient presents with:
- floaters
- the patient notes that symptoms have been present for a few weeks
examination you note that there is:
- a slight visual fields defecits
- What is the most likely diagnosis?
Retinal detachment
What does the image below show?
retinal detachment
pale area is fluid accumulation
what is retinal detachment?
An acute or progressive condition in which the neuro retina separates from the retinal pigment epithelium
there is an accumulation of sub- retinal fluid and loss of retinal function
what type of retinal detachment is most common?
Secondary Due to traction - usually retinal tear
what are the three types of retinal detachment
- primary(rhegmatogenesis)
- secondary
- exudative
what causes floaters?
Either traction or vitreous haemorrhage
do floaters and flashes always mean pathological retinal detachment?
No they can be benign detachments which do not lead to retinal detachment
how do you manage retinal detachment is?
laser for tears
surgery
what is a complication which can occur due to retinal detachment?
Proliferative vitreoretinopathy
what is hysterical blindness?
Functional neurological symptom disorder
what is the difference between conversion disorder and hysterical blindness?
conversion disorder Is when blindness is precipitated by a stressor
what’s is the DSM five criteria of hysterical blindness?
- one symptom of altered vocabulary motor or sensory function
- clinical findings showing incompatibility between symptoms and recognised medical disorders
- symptoms are not better explained by other medical or mental conditions
- symptoms cause clinically significant distress or functional/social impairment
what is the difference between acute and chronic hysterical blindness/ what the other two ways of classifying it?
Acute lasting under six months
chronic lasting over six months
persistent
episodic
what is the characteristic feature of hysterical blindness?
there is tunnelling of vision
How would you manage hysterical blindness?
Reassurance and explanation
psychotherapy
occupational therapy
medications such as SSRIs
what is squint?
a.k.a. strabismus.
- Misalignment of the eyes where one eye fixates on the chosen object
- the other is deviated
what is the presentation of strabismus in adults?
Diplopia and visual confusion – seeing the different objects in one place
what is the presentation of strabismus in children?
usually asymptomatic
is found on screening but causes ambylioplopia
what is acquired strabismus?
the malfunction of one or more cranial nerves namely:
- oculomotor (three)
- trochlear (four)
- abducens (six)
plus abnormal eye movements
what is reactive strabismus?
Mechanical restriction of eye movements due to conditions like graves or orbital fractures
what is the sensory strabismus?
Reduction in visual acuity of one eye
what is acute onset strabismus?
Usually caused by intracranial processes such as:
- mass lesions
- infarcts
- increased intracranial pressure
Acute onset history
can be:
- recurrent
- consecutive(occurs more thanonce but w different causes each time)
- residual (treatment not fully successful)
what what pathologies can strabismus be associated with?
- MG
- super nuclear palsys
- global developmental delay such as cerebral palsy
- any causes of acute onset strabismus:
- mass lesions
infarcts
increased intracranial pressure
what is the management of strabismus?
If there is an underlying cause treat that
refractory errors treated with glasses
ambyloplopia or diplopia corrected by covering the functional eye
what is ambyloplopia?
visual impairment resulting from abnormal visual stimulation during childhood
due to eye misalignment
but not attributable to structural abnormalities of the eye or of visual pathways
what is the difference between strabismus and ambyloplopia?
Strabismus, the medical term for “crossed-eye”, is a problem with eye alignment, in which both eyes do not look at the same place at the same time.
Amblyopia, the medical term for “lazy-eye”, is a problem with visual acuity, or eyesight.
what the causes ambyloplopia?
caused by misalignment of the eyes
- for accurate binocular vision each eye must have a clear focus aligned vision
what muscles does the oculomotor nerve Innervate?
- superior, inferior and medial rectus
- inferior oblique
- as well as ciliary muscles
- pupillary reflex muscles
what is the function of the oculomotor nerve?
elevation and intorsion (medially and down out)
rotation of the eye up and in
eye lid opening
pupilary consitriction
accommodation
what are causes of oculomotor nerve palsy?
diabetic neuropathy + hypertension ( causing micro-angiopathy)
compression or trauma from PCA aneurysms or base of skull fractures
What muscles does the trochlear nerve innervate?
innervate the superior oblique
what is the movement that the trochlear nerve causes?
rotating the eye clockwise ( so down and in)
what other common causes of trochlear nerve palsy?
microangiopathy
- by diabetic neuropathy
- hypertension
trauma
fourth nerve palsy (congenital)
atherosclerosis
cavernous sinus thrombosis