Ophthalmology - Retinal diseases Flashcards
An 82 year old lady presents with a 2 year history of gradually deteriorating vision. Describe the aetiology and risk factors of ARMD.
Caused by various consequences of molecular aging. Risk factors: - increasing age - caucasian ethnicity - FHx - smoking - CVD risk factors (wet AMD) - high cumulative lifetime exposure to sunlight
An 82 year old lady presents with a 2 year history of gradually deteriorating vision. Describe the 2 subtypes of ARMD.
- Dry AMD (90%)
- deposition of soft large drusen (lipids, vitronectin + other proteins) in RPE and between RPE + Bruch’s membrane… slow progressive atrophy of local RPE
- gradual vision loss as atrophy becomes more extensive - Wet AMD (10%)
- choroidal neovascularisation (between RPE + Bruch’s membrane) from periphery to centre… leaking of intravascular serous fluid + blood… disciform scarring sudden localised elevation of macula and/or detachment of RPE.
- visual loss wks-3 yrs
An 82 year old lady presents with a 2 year history of gradually deteriorating vision. She is diagnosed with dry AMD affecting both her eyes. What symptoms would you expect her to experience?
- painless decreased VA (esp. for near vision) and contrast sensitivity
- abnormal dark adaptation
- photopsia and light glare
- central scotoma
- +/- Charles Bonnet syndrome
An 82 year old lady was diagnosed 10 years ago with dry AMD. She presents to the ophthalmologist with new onset visual symptoms and is diagnosed with wet AMD. Which symptoms might she have been experiencing?
- metamorphopsia
- rapid deterioration in VA inc. profound central visual loss (haemorrhage) or shower of floaters (retinal detachment)
Which examinations / investigations would you perform on a patient presenting with ?ARMD and what would you expect to see in the 2 types?
- fundoscopy
- dry: drusen in macular area, hypo- or hyperpigmentation of peripheral retina (GA of RPE)
- wet: well-demarcated red patches (intraretinal or subretinal haemorrhages) or fluid, patchy greyish-green discolouration, disciform scarring - Colour fundus photography: to evaluate disease progression
- Fluorescence angiography: to ID wet ARMD (abnormal vessels leak the dye)
- Ocular coherence tomography (OCT)
- dry: drusen seen as undulations or RPE
An 82 year old lady with visual loss is diagnosed with dry AMD. How would you manage her?
- Lifestyle modification to slow disease progression e.g.
- avoid RFs - smoking cessation
- improve diet e.g. high in leafy green veggies + fish
- antioxidant Tx e.g. AREDS2 formula: vitC + E, lutein, zinc + copper - visual rehabilitation + visual aids e.g. magnifying glass
A healthy 82 year old lady with visual loss is diagnosed with wet AMD. How would you manage her?
1st line: monthly intravitreal VEGF inhibitor injection (e.g. becavizumab, ranibizumab) - most will maintain current level of vision, 1/3 will gain some improvement, 10% will not respond
2nd line: laser coagulation
Describe the blood supply + drainage of the retina.
Arterial supply via terminal branches of ophthalmic artery:
- central retinal artery - retinal circulation for inner 2/3 of retina
- posterior ciliary arteries - choroidal circulation for outer 1/3 of retina
Venous drainage via central retinal vein which drains into superior ophthalmic vein and then into cavernous sinus.
Which retinal vessel occlusion is most common?
Retinal vein occlusion (esp. BRVO)
Describe the common causes of RAO.
Retinal artery occlusion causes retinal ischaemia.
- embolism
- from carotid artery atherosclerosis (most common)
- atrial emboli e.g. from AF - thrombosis due to atherosclerosis
- vasculitis (much rarer) e.g.
- GCA
- inflammatory arteriris in younger pts e.g. polyarteritis nodosa, SLE or syphilis
Describe the common causes of RVO.
- systemic diseases: atherosclerosis, HTN, DM
- hypercoagulable/prothrombotic states e.g. polycythaemia vera. sickle cell anaemia, COCP
- ophthalmic e.g. glaucoma (increased IOP causing pressure on retinal vein)
A 60 year old male presents with suspected CRAO. Which symptoms would he likely complain of? What might you find on examination?
Symptoms: sudden, painless loss of vision in 1 eye.
POHx of amaurosis fugax may be present.
O/E:
- RAPD
Fundoscopy:
- grayish-white (cloudy) discolouration of entire retina (due to oedema within nerve fibre layer)
- cherry-red spot at fovea (no nerve fibres present at avascular foveal zone so not affected by oedema so underlying choroid is clearly visible)
- attenuation/cattle-trucking of arterioles
A 60 year old man presents with a 20 min history of sudden painless loss of vision in his right eye. He is diagnosed with CRAO. How would you manage him in the immediate and long term?
Immediate - attempt to dislodge thrombus (no evidence base:
- ocular massage
- paracentesis to remove fluid from AC to decrease IOP
- decrease IOP with 500 mg IV acetazolamide
Long term:
- ID and treat reversible RFs e.g. check + manage BP, blood glucose, cholesterol, etc. or check CRP + temporal artery biopsy + steroids if GCA suspected
What are the 2 subtypes of CRVO? How do these differ in presentation?
- Non-ischaemic CRVO (75%)
- venous stasis retinopathy
- Sx: subacute, mild-moderate loss of vision in affected eye
- O/E: RAPD absent
- fundoscopy: a few dot + blot and/or flame haemorrhages in all 4 retinal quadrants
- 1/3 develop into ischaemic CRVO - Ischaemic CRVO (25%)
- haemorrhagic retinopathy
- Sx: sudden, severe loss of vision in affected eye
- O/E: RAPD present
- fundoscopy:- many dot + blot and/or flame haemorrhages in all 4 retinal quadrants venous thickening (blood and thunder appearance)
- cotton wool spots (caused by swelling of ischaemic retinal nerve fibres)
- severe macular oedema
- severe papilloedema
How would a person with BRVO present? What would you find on examination?
Usually asymptomatic (unless macula involved).
Fundoscopy: dot + blot/flame haemorrhages in quadrant drained by affected branch.
+/- cotton wool spots
