Ophthalmology Flashcards
What is the most common cause of blindness in the UK?
age-related macular degeneration
What are the risk factors for age-related macular degeneration?
- > 75yo
- smoking
- family history
- IHD
- HTN
- dyslipidaemia
- diabetes mellitus
How is age-related macular degeneration classified?
Dry macular degeneration:
- 90% of cases
- atrophic
- drusen (in Bruch’s membrane)
- early age related degeneration
Wet macular degeneration:
- 10% of cases
- exudative or neovascular
- choroidal neovascularisation
- leakage of serous fluid and blood causing rapid loss of vision
- worst prognosis
- late age related degeneration
Features of age related macular degeneration:
- reduced acuity
- overall deterioration of night vision
- fluctuations day to day
- photopsia and glare around objects
- distortion line perception (Amsler grid testing)
- wet ARMD - red patches
How is age related macular degeneration investigated?
- slit lamp microscopy
- fluorescein angiography if neovascular to guide intervention
- ocular coherence tomography
How is age related macular degeneration treated?
- anti-VEGF: inhibits potent mitogen which drives vascular permeability in wet ARMD e.g. ranibizumab, bevacizumab, pegatanib (4 weekly injections)
- laser photocoagulation to slow progression where new vessels form
What is acute angle closure glaucoma and what are the predisposing factors?
- optic neuropathy due to raised IOP
- secondary to impairment of aqueous outflow
- predisposing factors: hypermetropia, pupillary dilatation, lens growth associated with age, mydriatic drops
What are the features of AACG?
- pain
- reduced acuity
- worse with mydriasis e.g. watching TV in dark room
- hard red eye
- halo around light
- semi-dilated non-reacting pupil
- corneal oedema -> dull hazy
- systemic upset
Management of AACG:
- emergency - urgent referral
- direct parasympathomimetic e.g. pilocarpine to contract ciliary muscle, open trabecular network and increase aqueous outflow
- beta blocker e.g. timolol to reduce aqueous production
- alpha-2 agonist e.g. apraclonidine which does both
- IV acetazolamide to reduce aqueous secretions
- definitive: laser peripheral iridotomy
What is anterior uveitis and what are the features?
- inflammation of the iris and ciliary body
- acute pain
- small, irregular pupil
- photophobia
- blurred vision
- redness
- lacrimation
- ciliary flush
- hypophon (pus in anterior chamber)
- impaired acuity
What is anterior uveitis associated with?
- ankylosing spondylitis
- reactive arthritis
- IBD
- Bechet’s
- sarcoidosis
How do you treat anterior uveitis?
- urgent review by ophthalmologist
- cycloplegics - to dilate pupil e.g. atropine, cyclopentolate, steroid eye drops
What are some ischaemic/vascular causes of sudden loss of vision and how is it treated?
- large artery disease e.g. atherothrombosis, embolus, dissection
- small artery disease e.g. temporal arteritis
- venous disease
- hypoperfusion
- ischaemic optic neuropathy
Treat with: aspirin 300mg
How does sudden loss of vision due to central artery occlusion present?
- afferent pupillary defect
- cherry red spot on pale retina
How does sudden loss of vision due to vitreous haemorrhage present and some causes?
- one of the most common causes
- sudden visual loss with dark spots and bleeds, red hue, reduced visual acuity
- caused by: proliferative diabetic retinopathy, posterior vitreous detachment, bleeding disorders, anticoagulation, ocular trauma
How does sudden loss of vision due to retinal detachment present?
- dense shadow peripherally progressing to central vision (curtain)
- straight lines look curved
- pigment in anterior vitreous
How does sudden loss of vision due to posterior vitreous detachment present?
- separation of vitreous membrane from retina
- painless loss of vision
- flashes of light (photopsia) in periphery
- floaters on temporal side of central vision
- cobweb across vision
What are the different types of blepharitis and features?
- inflammation of eyelid margins
- meibomian gland dysfunction: posterior blepharitis
- seborrhoea dermatitis/staph: anterior blepharitis
- features: bilateral discomfort, grittiness, sticky, red margins, styes and chalazions, secondary conjunctivitis
Management of blepharitis:
- soften using hot compresses twice a day
- lid hygiene
- artificial tears for symptom relief with dry eyes
How does diabetic retinopathy come about?
- hyperglycaemia leads to increased retinal blood flow and metabolism of vessel walls
- increased vascular permeability forms exudates
- pericyte dysfunction leads to micro aneurysms
- neovascularisiation due to growth factor response to retinal ischaemia
What is the new classification of diabetic retinopathy?
Mild:
- 1 or more microaneurysms
Moderate:
- microaneurysms
- blot haemorrhages
- hard exudates
- CWS, venous beading/looping, IRMA
Severe:
- blot haemorrhages and microaneuryssm in 4 quadrants
- venous beading in at least 2 quadrants
- IRMA in at least 1 quadrant
What is proliferative retinopathy?
- neovascularisation leading to haemorrhage
- fibrous tissue anterior to retinal disc
- more common in type 1 diabetes (blindness in 5 years)
- use pan retinal photocoagulation
What is maculopathy?
- hard exudates on background of change on macula
- check visual acuity
- more common in T2DM
What causes optic neuritis and what are the features?
- causes: MS, diabetes, syphilis
- features: unilateral reduced acuity over hours/days, red desaturation, pain worse on movement, RAPD, central scotoma
How do you treat optic neuritis?
high dose steroids - recovery in 4-6 weeks
How does central retinal vein occlusion present and what are some risk factors?
- sudden unilateral painless loss of vision
- sever retinal haemorrhages on fundoscopy
- risk factors: age, polycythaemia, glaucoma
What is a stye, different types?
- infection of glands in eyelid
- external: staph infection of glands of Moll
- internal: Meibomian glands - may leave residual chalazion
What is a chalazion?
retention cyst of Meiboomian gland - firm painless lump in eyelid
What is primary open angle glaucoma?
- optic neuropathy associated with increased IOP due to the peripheral iris covering the trabecular network (where aqueous humour drains from the anterior chamber)
- risk factors: age >40, genetic, black, myopia, HTN, DM, steroids
- has hereditary component so screen annually from 40yo
What is seen on investigations for primary open angle glaucoma?
- automated perimetry: peripheral visual field loss (nasal scotoma, tunnel vision)
- reduced acuity
- fundoscopy: optic disc cupping (cup:disc >0.7), optic disc pallor (atrophy), bayonetting of vessels, cup notching, disc haemorrhages
- application tonometry to measure IOP >24mmHg
- central corneal thickness measurement
- gonioscopy to assess peripheral anterior chamber
1st and 2nd line treatment for POAG:
1st: prostaglandin analogues e.g. latanoprost
2nd: beta blockers, carbonic anhydrase inhibitors, sympathomimetic
also surgery/laser treatment
How do prostaglandin analogues work?
- e.g. latanoprost
- increases uveoscleral outflow
- once a day
- ADR: brown pigmentation iris, increased lash length
How do beta-blocker eye drops work?
- e.g. timolol, betaxolol
- reduced aqueous production
- avoid in asthmatics and heart block
How do sympathomimetics work?
- e.g. brimonidine alpha-2 adrenoceptor agonist
- reduces production and increases outflow
- avoid if taking MAOI or TCA
- ADR: hyperaemia
How do carbonic anhydrase inhibitors work?
- e.g. dorzolamide
- reduces production
- systemic absorption may cause sulphonamide like reactions
How do miotics work?
- e.g. pilocarpine muscarinic receptor agonist
- increases uveoscleral outflow
- ADR: constricted pupil, headache, blurred vision
What are the causes of cataracts?
- old age
- smoking
- alcohol
- trauma
- diabetes
- long term steroids
- radiation
- myotonic dystrophy
- hypocalcaemia
What are the features of cataracts?
- reduced vision, colour vision
- glare and haloes
- defect red reflex
- cataracts visible on ophthalmoscopy (after dilation) and with slit lamp
Classification of cataracts:
- nuclear: change in lens refractive index, common in old age
- polar: localised, inherited, lie in visual axis
- sub scapular: steroid use, deep to lens capsule, in visual axis
- dot opacities: common in normal lenses, diabetes and myotonic dystrophy
Management of cataracts:
- non surgical: stronger glasses/contact lenses
- surgical: only effective treatment - replace with artificial lens
Surgical complications of cataracts surgery:
- posterior capsule opacification (thickened lens capsule)
- retinal detachment
- posterior capsule rupture
- endophthalmitis
What is herpes zoster ophthalmicus?
- reactivation of VZF in the area supplied by the ophthalmic division of trigeminal nerve
- vesicular rash around the eye area
- Hutchinson’s sign
Treatment and complications of herpes zoster ophthalmicus:
- oral antivirals 7-10 days, start within 72 hours
- IV Abx if severe or immunocompromised
- topical steroids for secondary inflammation of eye
- ocular involvement - urgent ophthalmology review
- complications: conjunctivitis, keratitis, episcleritis, anterior uveitis, ptosis, post-herpetic neuralgia
How does Horner’s syndrome present?
- miosis
- ptosis
- enopthlamos
- anhidrosis
Presentation of central lesions of Horner’s syndrome:
- anhidrosis of face, arm and trunk
- stroke
- syringomyelia
- MS
- tumour
- encephalitis
Presentation of pre-ganglionic lesions of Horner’s syndrome:
- anhidrosis of the face
- Pancoast tumour
- thyroidectomy
- trauma
- cervical rib
Presentation of post-ganglionic lesions of Horner’s syndrome:
- no anhidrosis
- carotid artery dissection
- carotid aneurysm
- cavernous sinus thrombosis
- cluster headache
How is hypertensive retinopathy classified?
Keith Wagener classification
I - arteriolar narrowing and tortuosity, increased light reflex, silver wiring
II - arteriovenous nipping
III - cotton wool exudates, flame and blot haemorrhages
IV - papilloedema
How does papilloedema appear on fundoscopy?
- venous engorgement
- loss of venous pulsation
- blurring optic disc margin
- elevation of disc
- loss of optic cup
- Paton’s lines (concentric retinal lines cascading from disc)
Causes of papilloedema:
- SOL
- malignant HTN
- idiopathic ICHTN
- hydrocephalus
- hypercapnia
Investigations to be carried out in vitreous haemorrhage:
- dilated fundoscopy (haemorrhage in vitreous cavity)
- slit lamp: RBCs in anterior vitreous
- US: rule of retinal tear/detachment
- fluorescein angiography: look for neovascularisation
- orbital CT: if open globe injury
How does herpes simplex keratitis presentation and how do you treat?
- dendritic corneal ulcer - shown by fluoroscein staining
- red, painful, photophobia, epiphora, reduced acuity
- treatment: immediate referral and topical acyclovir
Difference in presentation between bacterial and viral conjunctivitis:
Bacterial:
- purulent discharge
- eyes stuck in morning
Viral:
- serous discharge
- recent URTI
- preauricular lymph nodes
Treatment of bacterial conjunctivitis:
- normally self-limiting and settles in 1-2 weeks
- topical Abs e.g. chloramphenicol eye drops 2-3 hourly
- topical fusidic acid if pregnant
- no contact lenses or sharing towels
- not school exclusion
What is keratitis and what are some causes?
- inflammation of cornea
- bacterial: staph aureus, pseudomonas (contact lenses)
- fungal
- amoebic: acanthamoebic keratitis (if exposure to soil or contaminated water)
- parasite: onchocercal keratitis
Presentation of keratitis, treatment and complications:
- red eye, pain, photophobia, foreign body, gritty, hypophon
- contact lens wearers should have same day referral to rule out microbial keratitis
- treatment: stop contacts, topical quinolone, cycloplegics for pain relief
- complications: corneal scarring, perforation, endophthalmitis, visual loss
What is orbital cellulitis and what is the difference to periorbital cellulitis?
- infection of fat and muscles posterior to orbital septum but not involving globe
- usually from URTI spreading
- medical emergency
- periorbital cellulitis: less serious, superficial infection anterior to orbital septum due to superficial injury
Risk factors for orbital cellulitis:
- childhood
- previous sinus infection
- lack of Hib vaccination
- recent eyelid infection
- ear or facial infection
What are the features of orbital cellulitis and how does it differ from preseptal cellulitis:
Orbital:
- redness and swelling
- severe ocular pain
- visual disturbance
- proptosis
- ophthalmoplegia
- eyelid oedema and ptosis
- drowsiness
Preseptal:
- no reduced visual acuity
- proptotis
Investigations and treatment for orbital cellulitis:
- afferent pupillary defect
- proptotis
- dysmotility
- oedema
- CT: inflammation of orbital tissues deep to septum, sinusitis
- blood culture and microbiological swab
- Treatment: admission for IV Abx
What are the ocular complications of RA:
- keratoconjunctivitis sicca (most common)
- episcleritis
- scleritis
- corneal ulceration
- keratitis
- iatrogenic: steroid induced cataracts, chloroquine retinopathy
What is Argyll Robertson pupil?
- neurosyphilis and diabetes
- small irregular pupils
- ARP: accommodation reflex present
- PRA: pupillary reflex absent
What is central retinal occlusion:
- sudden unilateral vision loss due to thromboembolism or arteritis
- afferent pupillary defect, cherry red spot on pale retina
What is episcleritis and treatment:
- red eye
- not painful
- watering, mild photophobia
- injected vessels mobile when gentle pressure applied
- phenylephrine drops can help to distinguish from slceritis
- Tx: conservative, artificial tears
What are some causes of dilated pupil (mydriasis):
- 3rd nerve palsy
- Holmes-Adie pupil
- traumatic iridoplegia
- topical mydriatics: tropic amide, atropine
- sympathomimetics: amphetamines, cocaine
- anticholinergics: TCA
What can be seen on investigation of posterior vitreous detachment and what is the treatment?
- ophthalmoscopy: Weiss ring
- all referred within 24 hours to rule out retinal tears and detachment
- Tx: symptoms gradually improve over 6 months, surgery if associated tear/detachment
What is allergic conjunctivitis and what is the treatment?
- bilateral conjunctival erythema and swelling
- prominent itch, swollen eyelids
- history of atopy
- Tx: first line - topical/systemic antihistamines; second line - topical mast cell stabilisers e.g. sodium cromoglicate
What are the risks of ocular trauma?
- hyphema - urgent referral
- increased IOP due to blockage of angle and trabecular network with erythrocytes
Treatment of preseptal cellulitis:
- referral to secondary care
- oral antibiotics e.g. co-amoxiclav
What is RAPD?
- Marcus Gunn pupil
- swinging light test: affected and normal eye dilated when light shone into affected
- lesion anterior to optic chiasm so nerve or retina
- causes: retinal detachment, optic neuritis
- afferent: retina -> optic nerve -> lateral geniculate body -> midbrain
- efferent: Edinger-Westphal nucleus -> oculomotor
What is retinitis pigmentosa?
- tunnel vision
- nightblindness
- black bone spicule shaped pigmentation in peripheral retina on fundoscopy
- mottling of retinal pigment epithelium
How does scleritis present:
- red eye
- painful compared to episcleritis
- watering and photophobia
- gradual decrease in vision
What causes tunnel vision:
- papilloedema
- glaucoma
- retinitis pigmentosa
- choroidoretinitis
- optic atrophy secondary to tabes dorsalis
