Ophthalmology Flashcards
What do you need to do before fundoscopy?
dilate pupil
-eg atropine
Describe optic disk
Colour
Contour
Cup
Circulation
3 causes of retinal haemorrhage
- Diabetic retinopathy
- SAH
- Valsalva
- Hypertensive retinopathy
What are cotton wool spots?
Micro infarcts
What are drusen?
Pale, round and grey –> sign of age-related macula degeneration
Black pigmentation in peripheral retina?
Retinitis pigmentosa (inherited retinal degeneration)
What is a scotoma?
Causes?
Blind spot
Lesion in the optic nerve, before the chiasm.
eg ON
Macular degeneration –> central scotoma
What is slit lamp for?
Examining anterior segment of the eye (in front of the vitreous body)
Where in the retina has the highest concentration of cones?
Macula
What do cones do?
Colour vision and acuity
What do rods do?
Outer retina, night vision
What provides O2 for outer retina?
Choroid
Test for visual acuity?
Snellens at 6m
What is a cataract?
Opacity/clouding of the lens.
Progressive over years.
Usuall b/l
RFs of cataracts?
Sunlight, age, smoking, alcohol, steroids, DM
‘The angle’ in open angle glaucoma is what?
Space between posterior cornea and anterior iris.
The space where aqueous humour leaves the eye.
Where is aqueous humour produced? What does it do?
Ciliary body
Circulates and nourishes the lens
What is chronic open angle glaucoma?
o/e?
Chronic, progressive optic neuropathy with characteristic changes in optic nerve head and corresponding visual field loss.
Enlarged optic disc cup. Progressive visual field loss –> tunnel vision.
Raised IOP >21.
Triad of glaucoma
- raised IOP (not always present)
- Abnormal cup:disc ratio
- VF defect (tunnel vision)
Screening for chronic open angle glaucoma
IOP
VF
Fundoscopy
Drops used in open angle glaucoma
- Timolol (reduces aq production)
- Latanoprost (increases outflow)
- Dorzolamide (reduces aq production)
Non-medical mx for glaucoma?
- Laser therapy (trabeculoplasty)
- Surgery (trabeculotomy)
Dry macular degeneration
- fundoscopy
- VF loss
- Atrophy of RPE, drusen
2. Central scotoma
Wet macular degeneration
- fundoscopy
- VF loss
- Choroidal neovascular membrane, leaking vessels, exudate, haemorrhage, scarring
- Distorted central vision
Mx of wet MD
Anti-VEGF injection
DDx of sudden visual loss
- Vascular [CRVO, CRAO]
- Inflammatory [ON]
- Retinal detachment
CRAO
- pres
- o/e
- Sudden, total (or altitudinal) painless loss of vision
- RAPD )
Cherry red spot at fovea
3 ix in retinal artery
- Carotid artery doppler
- Fasting serum lipid
- ECG, FBC, CT head, Clotting screen
What is amaurosis fugax?
Loss of vision for 30 mins (ocular TIA)
CRVO
- pres
- o/e
- sudden painless u/l loss of vision
2. flame haemorrhages, leaking veins, intact arteries, swollen optic disc
mx of CRVO
- Anti-VEGF injection e.g. Ranibizimab
2. pan retinal photocoagulation
How to identify retinal non perfusion?
RAPD
Blots + microinfarcts
Fluorescein angiography
What is anterior ischaemic optic neuropathy?
Assos?
- Sudden visual loss due to disruption of bloody supply to the head of the optic nerve
- GCA