Ophthalmology Flashcards
(57 cards)
1
Q
Open angle glaucoma definition
A
Damage of optic nerve head with progressive loss of ganglion cells. Progressive of visual field.
2
Q
Open angle glaucoma aetiology
A
- Loss of retinal ganglions and their axons
- Accompanied by raised IOP
- Reduced flow through trabecular meshwork (absorbs aqueous humour) = painless, chronic degeneration
3
Q
Open angle glaucoma risk factors
A
- Raised IOP, >26mmHg or systemic HTN
- Myopia
- Diabetes
- FHx
- Afro-Caribbean ethnicity
- Prolonged steroid use
- Restricted ocular blood flow: diabetic retinopathy, central retinal vein occlusion.
- Eye trauma
- Uveitis
4
Q
Open angle glaucoma presentation
A
- Majority asymptomatic
- Early disease: peripheral vision loss which is covered by other eye
- Late disease: central vision loss and decreased visual acuity
5
Q
Open angle glaucoma investigation
A
- Gonioscopy: measures angle between cornea and iris
- Corneal thickness: influences IOP reading
- Tonometry: measures IOP
- Optic disc exam
- Visual field assessment
6
Q
Open angle glaucoma management
A
- Set target IOP depending on degree of damage
- Drugs that reduce IOP = beta-blocker, prostaglandin analogue
- Laser treatment tried after 2 unsuccessful attempts with pharmacological treatment
7
Q
Acute angle closure glaucoma definition
A
- Emergency
- Acutely raised IOP
- Causes anterior chamber angle to be obstructed
8
Q
Acute angle closure glaucoma risk factors
A
- Female gender (4:1)
- Asian
- Age
- Fhx
- Narrow eyes, thin iris, thick lens, shorter axial length of eyeball
9
Q
Acute angle closure glaucoma aetiology
A
- Anterior angle = junction of iris and cornea at periphery of anterior chamber.
- Iris opposed to trabecular meshwork (lies around circumference of angle) and block off aqueous drainage.
- Causes IOP to rise
Primary causes:
- naturally narrow angle
- iris pushed forwards as lens grows
- pupillary dilation
Secondary causes:
- forces exerted on iris
- trabecular meshwork blocked by a) blood b) blood vessels (diabetes) c) proteins
10
Q
Acute angle closure glaucoma presentation
A
- Pain: severe, rapid. Orbital and associated frontal / generalised headache.
- Blurred vision progressing to visual loss
- Coloured halos around lights: mild
- General malaise inc. N+V
- Eye: red - more marked around cornea periphery.. Non-reactive mid-dilated pupil.
11
Q
Acute angle closure glaucoma investigation
A
Clinical diagnosis based on at least two of:
- ocular pain
- N+V
- intermittent blurred vision with halos and 3 of
- raised IOP
- conjunctival infection
- mid-dilated non-reactive pupil
- corneal epithelial oedema
12
Q
Acute angle closure glaucoma management
A
Immediate referral to save sight
- Medical: topical beta-blockers / steroids / phenylephrine, plus UV acetazolamide.
- Surgical: to re-open angle
13
Q
Orbital cellulitis definition
A
- Ophthalmic emergency
- Infection of soft tissues behind the orbital septum
14
Q
Orbital cellulitis aetiology
A
-Local or haematogenous spread
Infection sources:
- peri-orbital structures
- pre-septal cellulitis
- direct from trauma
- post-surgery
- bacteraemia
Pathogens:
- S. pneumoniae
- S. aureus
- S. pyogenes
- H. influenzae
- MRSA
15
Q
Orbital cellulitis presentation
A
- Anterior: acute onset unilateral of conjunctiva + lids, oedema, erythema, pain, chemosis (oedema)
- Orbital: proptosis, pain with eye movement, blurred vision, decreased acuity, diplopia, RAPD
- Systemic: fever, malaise
16
Q
Orbital cellulitis investigation
A
Clinical diagnosis, investigations to identify source
17
Q
Orbital cellulitis management
A
Emergency to secondary care
- IV Abx for 7-10 days
- Optic nerve monitored every 4 hours
- Surgery if CT evidence of orbital collection and no response to Abx
18
Q
Giant cell arteritis definition
A
Immune-mediated vasculitis which can cause sudden and potentially bilateral vision loss
19
Q
Giant cell arteritis risk factors
A
- Women (3:1)
- European
- FHx, or of PMR
20
Q
Giant cell arteritis presentation
A
- Temporal headache
- Scalp tenderness
- Myalgia
- Fever, malaise
- Jaw claudication, comes on gradually during chewing
- Diplopia
- Abnormality of temporal artery = absent pulse, beaded, tender, enlarged
21
Q
Giant cell arteritis investigation
A
- Temporal biopsy
- ESR, CRP, LFTs, ferritin
22
Q
Giant cell arteritis management
A
Steroids: immediate high dose corticosteroid
Aspirin: low dose, decreases rate of visual loss and stroke
23
Q
Conjunctivitis definition
A
Inflammation of conjunctiva
24
Q
Conjunctivitis aetiology
A
Viral:
- adenovirus
- HSV / VZV
- Molluscum contagiosum
- Feature of systemic viral condition
Bacterial:
- staph
- S. pneumoniae
- H. influenzae
- M. catarrhalis
Allergenic:
- seasonal allergy
- perennial (daily)
- giant papillary conjunctivitis
25
Conjunctivitis presentation
Symptoms:
- red eye (bilateral)
- irritation / grittiness
- discharge: watery, mucoid, sticky or purulent
Signs:
- conjunctival injection
- chemosis
- follicles and papillae
26
Conjunctivitis investigation
History:
- recurrent URTI / infectious contact
- morning discharge and stickiness
- glasses / contacts
- eye trauma
Exam:
- general malaise
- Pre-auricular lymphadenopathy
- Orbital cellulitis,blepharitis, herpetic rash, nasolacrimal blockage
- Fundoscopy if unsure
27
Conjunctivitis management
Bacterial: slef-limiting so supportive.
Viral: supportive - cool compress, artificial tears, lubricant eye drops, cleansing
Allergic: prevent release of allergic mediators.
- Avoid eye rubbing and contacts, cool compresses to sooth.
- Pharmacological: topical mast cell stabilisers / antihistamines, topical / oral corticosteroids
28
Uveitis definition
Inflammation of uveal tract (= iris + ciliary body + choroid plexus)
- Anterior: iris
- Intermediate: vitreous + posterior ciliary body
- Posterior: choroid
- Panuveitis: throughout
29
Uveitis aetiology
Inflammatory cells and sustained production of cytotoxic cytokines
- Inflammatory: autoimmune
- Infectious
- Infiltrative secondary to neoplastic
- Trauma: commonly anterior
- Iatrogenic: surgery, medication
- Ischaemic: impaired circulation
30
Uveitis presentation
Anterior: unilateral. pain, redness, photophobia, progressive over hours / days, blurred vision, excess tear production, associated headache
Posterior: gradual visual loss, bilateral, occasional photophobia
Intermediate: painless floaters, decreased vision, minimal external signs
31
Uveitis investigation
- Slit lamp exam
| - SSx normal but uveitis granulomatous, further investigations e.g. FBC, ESR, ANA, HLA to investigate cause
32
Uveitis management
Control inflammation, prevent visual loss and minimise long term complications.
- steroids
- cycloplegic mydriatic drugs to paralyse ciliary body
- immunosuppressants
- surgery considered if severe or intractable
33
Diabetic retinopathy definition
Chronic progressive and potentially sight-threatening disease of retinal microvasculature associated with prolonged hyperglycaemia of DM.
34
Diabetic retinopathy epidemiology
Most common cause of sight loss in working age group
35
Diabetic retinopathy aetiology
- Macrovascular occlusion causes retinal ischaemia
- This leads to AV shunts and neovascularisation
- Leakage causes intraretinal haemorrhage and oedema
36
Diabetic retinopathy risk factors
- Increased severity / length of time of hyperglycaemia
- HTN / CVD risk factors
- Renal disease: proteinuria and elevated urea / creatinine
- Pregnancy
37
Diabetic retinopathy presentation
Symptoms:
- Painless gradual reduction of central vision
- Sudden onset dark painless floaters (due to haemorrhage)
Signs:
- Microaneurysms
- Hard exudates: precipitates of lipoproteins leaking from retinal blood vessels
- Haemorrhages: 'flame' haemorrhages seen tracking along nerve fibres
- Cotton wool spots: axonal debris due to poor metabolism at ischaemic infarcts
- Neovascularisation: attempt by healthy retina to re-vascularise hypoxic tissue
38
Diabetic retinopathy management
Primary: glycaemic / lipid / BP control, weight loss, smoking cessation
Ophthalmic intervention: most do not need treatment. Laser treatment to induce regression of neovascularisation and reduce central macular thickening. Anti-vascular endothelial growth factor. Intravitreal steroids.
39
Diabetic retinopathy complications
Visual loss secondary to:
- macular oedema / ischaemia
- haemorrhage
- tractional retinal detachment
40
Age-related Macular Degeneration definition
Ageing changes without other precipitating factor that occur in the macula in individuals aged 55+.
41
Age-related Macular Degeneration aetiology
Appearance of drusen (yellow lipid deposits) in macula, accompanied by:
wet: choroidal neovascularisation
dry: geographic atrophy
Dry:
- Soft drusen
- Atrophy of RPE progresses over time
- Can advance and cause vision loss without progressing into wet
- Progression to visual loss is gradual
- End stage: whole macula affected
Wet:
- New blood vessels grow under retina
- Spread under / over RPE, are fragile and leak easily
- Causes haemorrhage and scar formation
- End stage = disciform macular degeneration
42
Age-related Macular Degeneration risk factors
- Smoking
- FHx - several gene associations
- CVD risk factors
- Caucasian
- Sunlight
43
Age-related Macular Degeneration presentation
General Symptoms:
- Painless deterioration of cental vision
- Reduction in visual acuity
- Loss of contrast sensitivity
- Size / colour of objects appearing differently in each eye
- Abnormal dark adaptation
- Photopsia
- Light glare
- Visual hallucinations
Dry symptoms:
- Gradual visual loss
- Scotoma: black patch affecting central visual field
Wet symptoms:
- Central visual blurring and distortion - straight lines appear wavy
- Rapid visual deterioration
- If bleed: sudden deterioration to profound central visual loss
Signs:
- Decreased acuity
- Drusen in macula
- Macular scar (late)
44
Age-related Macular Degeneration management
Dry: no treatment, lifestyle adjustments slow progression
Wet: intravitreal injection of anti-VEGF - prevents neovascularisation
45
Cataracts definition
Lens opacities that become large enough to block light / obstruct vision
46
Cataracts aetiology
- New lens fibres generate from lens epithelium, old fibres not removed
- transparency maintained by lens protein alignment
- Disruption of fibres affects structure leading to protein aggregation
- Cataracts result from deposition of aggregated proteins in lens causing clouding, scattering, and vision obstruction
- Accumulation of yellow brown pigment in lens which affects colour vision and contrast
47
Cataracts presentation
Symptoms:
- Gradual painless visual loss
- Diplopia
- Haloes
Signs:
- Deflects in red reflex
- Visual acuity not improved by pin hole
- Normal pupillary reactions
48
Cataracts management
Phacoemulsification surgery
49
Amaurosis Fugax definition
Unilateral, painless, transient vision loss
50
Amaurosis Fugax aetiology
Transient ischaemia of retina from various pathologies:
- Occlusive artery disease: atherosclerosis, cardiac thrombo-emboli, arteritis
- Reduced perfusion pressure: postural hypotension, multiple occlusions of extracranial cerebral arteries, AV fistula, IC HTN, glaucoma
- Increases resistance to retinal perfusion: malignant hypertension, migraine, increase in blood viscosity, vasospasm
51
Amaurosis Fugax presentation
- Rapid onset blindness (within 15secs) lasting up to minutes
- Curtain drawn up / down over eye
- Clears slowly and uniformly from reverse direction
52
Amaurosis Fugax investigation
- Non-invasive tests for carotid blood flow and lumen diameter
- Angiography considered
53
Amaurosis Fugax management
Depends on test results
| If as a result of atherosclerosis, give anti-platelet e.g. aspirin
54
Optic neuritis definition
Inflammation of the optic nerve
55
Optic neuritis aetiology
Various causes:
- Acute demyelinating: associated with MS
- Ischaemic: GCA, diabetic papillopathy
- Inflammatory: AI disease = sarcoidosis, SLE
- Infection: TB, syphillis
- Nutrition: B12 deficiency
- Drugs: amiodarone, isoniazid
- Children: viral infection
56
Optic neuritis presentation
Symptoms: triad of;
- visual impairment developing over hours to days and made worse by hot bath
- eye pain worse on movement
- disturbance of colour vision
Signs:
- Decreased pupillary light reaction in affected eye: RAPD
- Varying degrees of visual loss
- Abnormal contrast sensitivity and colour vision
- Scotoma
57
Optic neuritis management
-Acute demyelinating: corticosteroids during acute phase
