Ophthalmology Flashcards Preview

Year 3 Special Senses > Ophthalmology > Flashcards

Flashcards in Ophthalmology Deck (57):
1

Open angle glaucoma definition

Damage of optic nerve head with progressive loss of ganglion cells. Progressive of visual field.

2

Open angle glaucoma aetiology

-Loss of retinal ganglions and their axons
-Accompanied by raised IOP
-Reduced flow through trabecular meshwork (absorbs aqueous humour) = painless, chronic degeneration

3

Open angle glaucoma risk factors

-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

Open angle glaucoma presentation

-Majority asymptomatic
-Early disease: peripheral vision loss which is covered by other eye
-Late disease: central vision loss and decreased visual acuity

5

Open angle glaucoma investigation

-Gonioscopy: measures angle between cornea and iris
-Corneal thickness: influences IOP reading
-Tonometry: measures IOP
-Optic disc exam
-Visual field assessment

6

Open angle glaucoma management

-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

Acute angle closure glaucoma definition

-Emergency
-Acutely raised IOP
-Causes anterior chamber angle to be obstructed

8

Acute angle closure glaucoma risk factors

-Female gender (4:1)
-Asian
-Age
-Fhx
-Narrow eyes, thin iris, thick lens, shorter axial length of eyeball

9

Acute angle closure glaucoma aetiology

-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

Acute angle closure glaucoma presentation

-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

Acute angle closure glaucoma investigation

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

Acute angle closure glaucoma management

Immediate referral to save sight
-Medical: topical beta-blockers / steroids / phenylephrine, plus UV acetazolamide.
-Surgical: to re-open angle

13

Orbital cellulitis definition

-Ophthalmic emergency
-Infection of soft tissues behind the orbital septum

14

Orbital cellulitis aetiology

-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

Orbital cellulitis presentation

-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

Orbital cellulitis investigation

Clinical diagnosis, investigations to identify source

17

Orbital cellulitis management

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

Giant cell arteritis definition

Immune-mediated vasculitis which can cause sudden and potentially bilateral vision loss

19

Giant cell arteritis risk factors

-Women (3:1)
-European
-FHx, or of PMR

20

Giant cell arteritis presentation

-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

Giant cell arteritis investigation

-Temporal biopsy
-ESR, CRP, LFTs, ferritin

22

Giant cell arteritis management

Steroids: immediate high dose corticosteroid
Aspirin: low dose, decreases rate of visual loss and stroke

23

Conjunctivitis definition

Inflammation of conjunctiva

24

Conjunctivitis aetiology

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