Opthamology Flashcards
What are the causes of conjunctivitis? What are the clinical features of each?
Allergic - generalised redness, serous discharge, itchiness, bilateral
Viral (adenovirus, Herpes simplex) - unilateral, generalised redness, serous discharge
Bacterial (S.pneumoniae, S.aureus, H.influenzae) - generalised redness, itchiness, purulent discharge, foreign body sensation/gritty
What is the management of each cause of conjunctivitis?
Allergic - antihistamine eye drops
Viral - self limiting, don’t touch eyes, can use artificial tears
Bacterial - normally self limiting, chlorampenicol drops in severe cases
What type of HSV causes conjunctivitis and how?
HSV 1 normally but HSV2 in neonates from contaminaiton in vaginal delivery.
What is blepharitis?
Inflam of the eyelid = sore and itchy crusty eyelids. Is a chronic condition and can’t be cured. 50 yo = average presentation.
What are the causes of different types of blepharitis and some specific signs for each?
Ant - staph, seborrheic dermatitis. Trichiasis, poliosis, madarosis
Post - affects meibomian gland. dilated and obstructed meibomian glands, chalazion
What do these words mean:
Trichiasis
Poliosis
Madarosis
T = eyelashes turning in
P = depigmentation of eyelashes
M = loss of eyelashes
What is the management of blepharitis?
Can’t be cured but:
Conservative management - warm compresses and clean lids reg, avoid eye make up and contact
Medical - ocular lubricants, steroids or abx
Can refer if not resolving or suspect underlying condition, visual change/loss, cellulitis signs and eyelid deformity
What do entropion and ectropion mean?
Entropion = eyelid turning inwards
Ectropion = eyelid turning outwards
What is keratitis? What are the CF?
Inflam of the cornea.
CF - eye pain, watering, photophobia, reduced vision, hypopyon
O/E - corneal infiltrate and opacification
What are corneal infiltrates? What is epiphora?
What is hypopyon?
Gray haze around cornea, looks a bit like corneal arcus
Epiphora - excess tearing of eye
Hypopyon - collection of pus behind the cornea in the ant chamber
Herpes simplex keratitis:
- CF
- O/E
- Treatment
Pain, photophobia, epiphora.
Can see dendritic ulcers w fluorescein, most common cause of corneal blindness.
Topical acyclovir.
What is the pathophysiology behind central retinal artery occlusion?
Int carotid artery branches into the ophthalmic artery which supplies the eye. This splits into retinal (retina) and ciliary (choroid) arteries.
What is the presentation of CRAO?
- Sudden onset painless unilateral loss of vision due to ischaemia of the retina
- Central area of vision spared due to cilioretinal artery supply to the macula in 15-30% of cases
What are the signs of CRAO? (fundoscopy)
- Relative afferent pupillary defect - asymmetrical pupillary reaction to light due to optic nerve disease
- Pale retina
- Cherry red spot = macular sparing due to choroid maintaining blood supply
- Retinal emboli
What is the management of CRAO?
- Intra arterial thrombolysis - limited evidence
- Treat underlying causes eg. IV steroids for temporal arteritis
What are the complications of CRAO?
- Profound visual loss
- Cardiovascular disease burden, more likely to die from stroke
- Neovascularisation of ischaemic retina = vitreous haemorrhage or occlude ant chamber = glaucoma
What is the difference between CRAO and CRVO?
CRVO is more common than CRAO and has widespread hyperaemia and haemorrhages on fundoscopy = stormy sunset.
What are cataracts and what are the causes?
Opacity in the lens due to denatured protein/loss of crystallin.
Causes - increasing age, trauma, steroids, ant uveitis, radiation
What are the CF of cataracts?
- Blurred vision
- Sensitive to bright lights and glare
- Poor night vision
- Halos around lights
- Polyopia
- Reduction in colour intensity
- Loss of red reflex
- Can see white/grey pupil
- Nystagmus
What is the management of age related cataracts?
Replace the diseased lens:
- Phacoemulsification - break up diseased lens and aspirating the contents, then place a new lens into the remaining lens capsule (most common)
- Extra capsular cataract extraction = remove whole nucleus and aspirate lens cortex then insert rigid lens
What are the complications of cataracts surgery?
- Endophthalamitis - infection of the viterous/aqueous
- Corneal oedema
- Malposition of lens
- Retinal detachment
- Post capsule rupture and opacification
What are the causes of cataracts in children?
- Inherited
- Systemic disease eg. intrauterine rubella, DM, myotonic dystropy craniofacial syndromes
- Idiopathic
- Drugs
- Trauma - penetrating injury, electric shock, blunt trauma
Quite a rare cause of blindness in children.
What are some drugs that cause cataracts?
- Steroids
- Amiodarone
- Phenothiazines
What are the sx of cataracts that affect the subcapsular of the lens?
Near vision affected more than distance
What are the sx of cataracts that affect the nuclear area of the lens?
Colours less well saturated and pt short sighted
What are the sx of cataracts that affect the cortical area of the lens?
Sx worse in the dark when the pupil dilates and exposes more of the cataract.
What is the uveal tract?
Iris - pigmented structure that controls the amount of light entering the eye
Ciliary body - produces aqueous humour and controls the thickness of the lens
Choroid - supplies essential nutrients and is richly vascular, removes waste product and absorbs light passing through retina
Mydriasis
Miosis
Mydriasis - dilation of the pupil, dillator pupillae - low light and sympathetic activation
Miosis - constriction of pupil, sphincter pupillae - lots of light and parasympathetic activation
What is the affect of the following drugs on the size of the pupil?
Tropicamide
Phenylephrine
Pilocarpine
Tropicamide - mydriasis
Phenylephrine - mydriasis
Pilocarpine - miosis
What are the different types of uveitis?
Ant uveitis - inflam of the iris and ciliary body
Post uveitis - inflam of retina and choroid
Panuveitis - inflam of whole uveal tract
What are some causes of ant uveitis?
Autoimmune = ankylosisng spondylitis, idiopathic juvenile arthritis, SLE, IBD, vasculitis esp granulomatosis w polyangitis, reactive arthritis
Infections = herpes, TB, syphilis, HIV
What are the CF of ant uveitis?
- Red eye
- Pain
- Blurred vision
- Photophobia
- Increased watering
- Circum corneal injection
- Irregular pupil due to synechiae
- Keratitic precipitates
What are synechiae? What is the risk of them?
Adhesions between the lens and the iris. Can cause obstruction of passage of aqueous humour (closed angled glaucoma?).
What is the management of ant uveitis?
- Topical steroids to reduce inflammation
- Antimuscarinic eye drops eg. cyclopentalate to prevent post synechiae, dilates pupil
What are the CF of post uveritis?
- Painless blurred vision
- Floaters
- Photopsia - perception of flashes of light
- Fundoscopy = choroiditis = raised pigmented lesions and retinitis = cotton wool spots and haemorrhages
What is retinal detachment?
Separation of the neural retina from the retinal pigment epithelium
What are the two layers of the retina?
- Neural retina - only attached at the optic nerve head
- Retinal pigment epithelium - firmly attached to Bruch’s membrane of the choroid
What are the CF of retinal detachment?
- Painless
- Floaters
- Photopsia
- Reduced visual acuity
- Visual field impairment
What is the danger of retinal detachment?
If detachment progresses to the macular sight may be lost and pt will be blind
What is the management of retinal detachment?
- Vitrectomy = removing and replacing vitreous humour
- Scleral buckling = attached a small band around the eye to push the wall of the eye and retina closer together
- Cryotherapy and laser therapy = sealing the tear in the retina
What are the causes of detached retina?
- Short sightedness
- Operation on the eye eg. cataract surgery
- Eye injury and trauma
- FH
What is a corneal ulcer?
A type of infective keratits where a layer of epithelium has been removed off the cornea. Starts as conjunctivitis and pink eye.
What are the causes of corneal ulcers/keratitis?
- Contact lenses
- Herpes and funal causes
- Bells palsy - eyelids don’t fully close
- Foreign body
- Abrasions to eye surface
- Severe allergic eye disease or dry eyes
What is angle closure glaucoma?
Closing/narrowing of the irido-corneal angle = reduced drainage of aqueous humour causing rising intra ocular pressure.
What are the CF of primary closed angle glaucoma?
- Systemically unwell = nausea and headache
- Severe ocular pain
- Blurred vision and halos around lights
- Fixed, dilated pupil
- Red eye
What are the RF of primary closed angle glaucoma?
- Increasing age
- Asian
- Long sightedness
- Women
- FH
What is the management of acute closed angle glaucoma?
EMERGENCY
- Antiemetics and analgesics
- 1st = IV acetazolamide = reduce aqueous production
- 2nd = oral glycerine w lemon juice or IV mannitol
- Topical B blockers = reduce aqueous production and topical steroids = reduce inflam
- Pilocarpine = increase uveoscleral outflow, cause miosis
- Once IOP controlled = peripheral iridectomy is definitive, often do prophylactically on other eye
What are the ix into acute closed angle glaucoma?
- Normally diagnosed based on clinical presentation
- Tonometry - measuring IOP, >30mmHg, normal = 8-21
- Gonioscopy - assesses ant chamber and drainage system
- Slit lamp - shows cupping of the optic disc due to increased IOP
What are the CF of chronic angle closure glaucoma? How is it treated?
Insidious onset w visual loss only apparent in advanced disease.
Pick it up on asymptomatic pt
Treat = laser peripheral iridotomy
What is chronic open angle glaucoma?
Optic neuropathy w death of optic nerve fibres, with or without raised IOP.
What are the CF of chronic open angle glaucoma?
- Normally diagnosed through screening, asymptomatic until advanced disease
- Loss of peripheral fields and then central scotoma in advanced disease - arcuate visual field defect
- Optic disc cupping
What is the management of chronic open angle glaucoma?
Prevent progression = set target IOP controlled by topical meds:
- Gold standard = laser trabeculoplasty
- If decline surgery = prostaglandins eg. latanoprost
- Reduce aqueous production = B block eg. timolol, carbonic anhydrase inhib
- Increase uveoscleral outflow = miotics, prostaglandin analogues (1st line)
What is dry age related macular degeneration?
- Progressive loss of central vision over years/decades
- Difficulty reading text and probs w vision in dim light
- Visual fluctuation = day by day vision deteriorates and improves
- Fundoscopy = drusen at the macular
What is wet age related macular degeneration?
- Progressive loss of central vision over months
- Same difficulties as dry AMD
- Fundoscopy = macular oedema and neovascularisation
How is diabetic retinopathy caused?
Poor glycaemic control = vascular occlusion and leakage = retinal ischaemia, neovascularisation and blindness
What are the types of diabetic retinopathy? What is the difference?
Non proliferative and proliferative = neovascularisation
What are the fundoscopy signs of diabetic retinopathy?
NPDR - microaneurysms, blot haemorrhages, hard exudates, cotton wool spots,
Proliferative - neovascularisation, vitreous haemorrhage
What are some of the complications of diabetic retinopathy?
- Retinal detachment
- Vitreous haemorrhage
- Optic neuropathy
- Cataracts
What is the management of diabetic retinopathy?
- Laser photocoagulation - pan retinal photocoagulation in proliferative diabetic retinopathy - get lots of burn marks on retina, 50% of pt have reduced visual field
- Vitreoretinal surgery
- Ranibizumab
What is diabetic maculopathy and what are the features on fundoscopy?
Macular oedema and ischaemic maculopathy
What are the CF of orbital cellulitis?
- Painful eye movements
- Diplopia
- Visual impairment
- Swollen eyelid, fever and redness
- Proptosis
What is the cause of orbital cellulitis?
Spread of infection from sinusitis or URTI
What are the complications of orbital cellulitis?
Infection spreads intracranially or cavernous sinus thrombosis - both can cause death
What is the management of orbital cellulitis?
- CT head
- ENT referral - surgery to decompress orbit, I+D of abscess
- IV abx
What is preseptal cellulitis?
Spread of infection from local facial or eyelid injuries, doesn’t spread past the orbital septum.
Has swollen eyelid, fever and erythema but not visual impairment, diplopia or painful eye movements.
What is the management of preseptal cellulitis?
Iv abx
What is scleritis associated w?
Rheumatoid arthritis but also other connective tissue diseases
What are the clinical features of scleritis?
- Deep pain that wakes pt at night, pain w eye movement
- Severely red eye
- Photophobia
- Reduced visual acuity
- Tenderness of palpation
- Topical vasoconstrictors don’t cause blanching of eye - distinguish episcleritis from scleritis
- Most commonly in middle ages women
What is the management of scleritis?
Ophthalmological emergency:
- Immunosuppression - methotrexate in RA
- NSAIDs
- Steroids
What are the RF of thyroid eye disease?
- FH Grave’s disease
- Smoking worsens
What is the pathophysiology behind thyroid eye disease?
Auto ab attack extraocular muscles = swelling behind eye = proptosis
What are the signs of thyroid eye disease?
- Lid retraction
- Proptosis
- Lid lag
- Red, watery eyes
What are the complications of thyroid eye disease?
- Exposure keratopathy = corneal damage and infection from not being able to close eyes
- Compressive optic neuropathy = retro orbital swelling compresses optic nerve
What are the cranial nerves that control the eye?
CN 3 (oculomotor) - all other muscles of ocular movement
4 (trochlear) - superior oblique = moves eye down
6 (abducens) - lateral rectus = mores eye laterally
What is anisocoria?
Abnormally sized pupils
What are some causes of unilateral large pupil?
- Traumatic iris damage
- Third CN palsy
- Dilating eye drops
- SAH and diffuse brain injury
What are some causes of unilateral small pupil?
- Uveitis w synaechiae
- Horner’s
- Constricting eye drops
In impaired pupillary light reflex how can u differentiate between the cause being a damaged optic nerve or damaged oculomotor nerve?
Optic nerve - when light shone in damaged eye no pupil change in either eye but when light shone in good eye both eyes constrict
Oculomotor nerve - when light shone in damaged eye the pupil of good eye constricts, when light shone in good eye no consensual reaction
What are some causes of relative afferent pupillary defect?
Normally optic nerve disease or severe retinal disease:
- GCA
- Optic neuritis
- Severe glaucoma
- Traumatic optic neuropathy
- Orbital disease
- Severe ischaemic retinal disease eg. CRAO
- Retinal detachment
- Amblyopia
What are some causes of bilateral non reactive pupiks?
- Extensive intracranial pathology
- Diffuse brain injury
- Brain stem herniation
- Brain death
Generally a sign of v bad prognosis
What are some causes of third nerve palsy?
- Myasthenia gravis
- Thyroid eye disease
- GCA
- Extradural haematoma
What does mydriatic and cycloplegic eye drops mean?
Mydriatic - cause pupil dilation
Cylcoplegic - paralysis of muscles of accommodation
Myrdiatic and cycloplegic eye drops:
- Use
- Eg
- Contraindications
U - dilate pupil for visualisation of retina, manage amblyopia
Eg. atropine, cyclopentolate, tropicamide, phenylephirine
C - can’t use any in untreated narrow angle glaucoma
What are the SEs of mydriatic and cycloplegic eye drops?
- Whitening of the eye lids
- Atropine = redness and warm face
- Mydriatics are a bit stingy
- Can’t drive until blurring effect worn off
What is the mechanism of atropine, cyclopentolate, tropicamide?
Parasympatholytic - anticholinergic blocks iris sphincter muscles and accom muscles of ciliary body
What is the MOA of phenylephirine?
Sympathetic agonist - stim of iris dilation muscle
What is the use of fluorescein drops?
- See defects on corneal epithelium
- Assess tear drainage in congenital nasolacrimal duct obstruction
- Stains damaged areas of eye
What is amblyopia?
Visual impairment from reduced visual stim during early childhood eg. squints, unequal refractive error, congenital cataracts
What is the management of amblyopia?
- Good eye patched
- Critical period is up to 8 yo
- Remove cataracts
- Correct a squint or poor visual acuity
Differentials for red eye?
- Conjunctivitis
- Infective keratitis
- Ant uveitis
- Acute closed angle glaucoma
- Scleritis
- Subconjunctival haemorrhage
What are the causes of painless loss of vision?
- Age related macular degeneration
- Chronic open angle glaucoma
- Diabetic retinopathy
- AION
- CRAO
- CRVO
- Retinal detachment
- Vitreous haemorrhage
- Optic neuritis
What are the causes of painful loss of vision?
- Acute closed angle glaucoma
- Ant uveitis
- Infective keratitis
Draw the central visual pathway
Answer on iPad or in anki cards
What is significant about visual fields?
Temporal visual field is detected by nasal retinal fibres and the nasal visual field is detected by temporal retinal fibres.
Superior radiations responsible for inf quadrant field and inf radiations responsible for sup quadrant field.
What are the different visual field defects?
- Monocular blindness - one eye completely blind eg. anopia
- Bitemporal hemianopia - tunnel vision
- Homonomous hemianopia - nasal visual field lost in one eye, temporal in the other
- Scotoma - area of reduced vision in other wise normal visual field
What visual field defect will result from an optic nerve lesion?
Monocular blindness, temporal and nasal fibres on the ipsilateral side are affected so the nasal and temporal visual fields are lost on the ipsilateral side.
Eg. Right optic nerve palsy = right monocular blindness
What visual field defect results from an optic chiasm lesion?
Bitemporal hemianopia:
- Nasal fibres of both sides affected = temporal visual fields both lost
- Pit adenoma can cause
upper quadrants > lower quadrants = pit adenoma
lower quadrants > upper = craniopharyngioma ??
What visual field defect results from an optic tract lesion?
Contralateral homonomous hemianopia:
- Eg. right optic tract lesion = nasal fibres of the left eye affected so left eye temporal field lost and temporal fibres of right eye affected so right eye nasal field lost
What visual field defect results from an optic radiation lesion?
eg. left sup radiation lesion = homonomous inf quadrantopia
Left sup radiation = inf right nasal and left temporal quadrants effected
What is amourosis fugax?
Transient loss of vision, like a curtain coming down = blockage of ophthalmic artery which is a branch of central retinal artery.
What is seen w fluroscein eye drops in a corneal abrasion?
Vertical linear defects in the corneal epithelium
What are the symptoms of optic neuritis?
- Visual impairment
- Pain around the eye, typically worse on eye movement
- Dyschromatopsia - impairment of colour vision
- Light flashes
- Increased symptoms w raised body temp eg. environment or exercise
- Alt perception of the direction of movement
What are the signs of optic neuritis?
PAINFUL REDUCED VA W PAIN ESP ON EYE MOVEMENTS w central scotoma and colour vision loss.
- Relative afferent pupillary defect
- Varying degrees of vision reduction
- Nasal steps
- Altitudinal and arcuate field defects
- Scotoma
- Papillitis
What is the management of optic neuritis?
- IV methylprednisolone, 1g for 3 days
- Brain MRI - info about risk of developing MS
- Most patients recover but there is a risk of recurrence
What does the pneumonic PITS stand for?
Parietal inf
Temporal superior
For quadrantopias
How do you manage wet age related macular degeneration?
Want to prevent further neovascularisation - anti VEGF injection - vascular endothelial GF
Managing wet vs. dry age related macular degeneration
Wet macular degeneration, speak of photcoagulation as that comes before photodynamic therapyl, intra vitreal ranibizumab (anti VEGF) helps them see.
But dry macular decline has no treatment at this time.
How can you remember the features of optic neuritis?
AFRRO
Acuity
Fields
RAPD
Red colour gone
Optic disc
What is endophthalmitis?
Is an infection of the vitreous:
Severe pain and profound vision loss
Hypopyon
Following cataracts surgery
ƒHow is endophthalmitis treated?
Intra vitreal abx
What is the management for CRVO?
- Neovasculisation - laser photocoagulation
- Macular oedema - anti VEGF
What are some features of HTN retinopathy?
Flame haemorrhages
Papilloedema
AV nipping
Cotton wool spots
Reduced VA
Silver wiring - thickened vessel walls
Hard exudates
What is the classification of HTN retinopathy?
Keith Wagener classification:
Stage 1 - Mild narrowing of the arterioles
Stage 2 - AV nipping and silver wiring
Stage 3 - Cotton-wool patches, exudates and haemorrhages
Stage 4 - Papilloedema
How do you manage HTN retinopathy?
Control BP and stop smoking
