Approach to Visual Loss (core)

Question 1

Which muscles elevate the eyelids?

Answer 1

Levator palprabrae superioris

Muller’s

Question 1

What are some causes of cataracts?

Answer 1

Age-related

Drugs - steroids, amiodarone

Trauma

Systemic disease - DM

Occular diseases - uveitis, myopia

Question 2

What is the most common cause of vision loss in diabetic retinopathy?

Answer 2

Diabetic macular oedema

Question 3

What causes vitreous haemorrhage?

Answer 3

Retinal detachment

Proliferative diabetic retinopathy

Trauma

Retinal tear

Question 6

What is the most common cause of visual loss?

Answer 6

Refractory error

Question 6

How do you perform a retinal massage?

Answer 6

Place pressure with finger on orbit firmly (until pain occurs) and release after 5-15s for 15mins

Question 7

How can you treat raised IOP?

Answer 7

Acetazolamide

Prostaglandin

Osmotic - manittol

Lazer the iris

Question 8

What is a cause of acute loss of vision and pain?

Answer 8

Trauma

Acute glaucoma

Question 8

What’s a cause of acute glaucoma?

Answer 8

Raised IOP

Question 10

What can you do in a case of central arterial occlusion?

Answer 10

Occular massage

Question 11

Which side of the visual field is the blind spot on?

Answer 11

Temporal

Question 12

What is a scotoma?

Answer 12

A blind spot

Question 13

What is the central visual axis?

Answer 13

Line that transects the lens and meets the fovea

Question 14

How do cataracts present?

Answer 14

Progressive vision loss

Loss of colour acuity

Question 15

What pathological process causes wet macula degeneration?

Answer 15

New angiogenesis

Question 16

What is RBCs in the anterior chamber called?

Answer 16

Hyphema

Question 17

What is the ICE-TEST for? What does it involve?

Answer 17

Myasthenia gravis

Ice the eye and look for improvement of ptosis

Question 18

What is Keratoconus?

Answer 18

Progressive thinning, weakness, and protrusion of the cornea

Question 19

What is papilloedema?

Answer 19

Swelling of the optic disc

Question 20

What are two causes of hyphema?

Answer 20

Trauma

Neovasculisation

Question 21

What is Fuch’s Endothelial Dystrophy?

Answer 21

Swelling of the corneal epithelium due to failure of fluid drainage

Question 21

What can cause diffuse intraretinal haemorrhage?

Answer 21

DM

Central retinal vein occlusion

Question 22

How do you treat wet macular degeneration?

Answer 22

VEGF inhibitors

Question 23

What causes central retinal vein occlusion?

Answer 23

Atherosclerosis

Inflammatory disease

Blood dyscrasias

Ophthalmic

Question 25

Do you get a RAPD with a central artery occlusion?

Answer 25

Yes

Question 26

What causes flash of light (photopsia)?

Answer 26

Retinal traction/detachment (transient) Migraine (longer)

Question 27

What is endophthalmitis?

Answer 27

Injury to multiple structures in the eye

Question 28

What is the mechanism of diabetic macular oedema?

Answer 28

Oedema into the retina with lipids left behind

Question 29

What is light saturation?

Answer 29

The appearance of a constant source of light in one eye compared to the other

Question 30

What causes a cherry red spot?

Answer 30

Central retinal artery occlusion

Question 31

What must you always test when examining the eye?

Answer 31

Acuity Pupils Pressure

Question 32

What are some causes of ptosis?

Answer 32

Neurogenic cause - CNIII palsy, horners Myogenic - MG, muscular dystrophy Aponeurotic cause - involution Mechanical - Orbit tumours, scarring, oedema Pseudoptosis - Contralateral Mitochondrial disease - Chronic Progressive external Ophthalmoplegia

Question 33

What is the pathophysiology of Horner's? Why do you get a ptosis?

Answer 33

Loss of the sympathetic innervation to the eye Because Muller's muscle is controlled by the sympathetic system

Question 34

If the patient has transient blurring of vision plus watering, would should you think of?

Answer 34

Tear-film disruption

Question 35

What is the aetiology of trachoma?

Answer 35

Chlamydia trachomatis

Question 36

What are the layers of the cornea?

Answer 36

Epithelium Basement membrane Stroma Descemet's Membrane Endothelium

Question 37

How is acute closed angle glaucoma managed?

Answer 37

Reduced IOP Acetazolamide Beta blocker - timolol Topical steroid Peripheral Iridotomy once IOP is reduced

Question 38

Does vision in a patient with cataract improve with pinhole?

Answer 38

No

Question 39

Who gets lens dislocation? What is the pathophysiology?

Answer 39

People with connective tissue disorders eg Marfans Usually pathology in the zonules

Question 40

How do vitreous haemorrhage present on Hx and Ex?

Answer 40

Hx of flashes of light and floaters in the affected eye Acute, painless vision loss - amaurosis fugax VA: \<6/60, PEARL, Nil RAPD

Question 41

What is a weiss ring?

Answer 41

Sign of posterior vitreous detachment

Question 42

How would differentiate vitreous haemorrhage and central retinal artery occlusion as causes of painless vision loss?

Answer 42

RAPD will be present in the affected eye in central retinal artery occlusion And signs on fundoscopy - Haemorrhage for the former - Cherry red spot for the latter

Question 43

What does a relative afferent pupil defect look like on exam? What does it reflect? Where is the pathology?

Answer 43

On the sling light test, when swinging to the affected eye both eyes will constrict less (or appear to dilate) cf to the unaffected eye. It reflects a weakness the transmission of the afferent signal (in response to light) along CNII The pathology is between the retina and the optic chiasm

Question 44

What are some causes of central retinal artery occlusion? Which must be ruled out urgently?

Answer 44

Atherosclerosis Embolic source Haematological conditions - hypercoagulable states Inflammatory condition - GCA which must be ruled out!

Question 45

Compare the Hx, pathophysiology, and Mx of dry vs wet macula degeneration

Answer 45

Dry - Hx: Gradual central vision loss (yrs), Central scotoma - Path: Loss of retinal pigment epithelium/photoreceptors - Mx: Supportive, smoking cessation, vitamins Wet - Hx: Rapid central vision loss (wk/months),Metamorphopsia, central scotoma - Path: Choroidal Neovascularization - Mx: Anti-VEGF intra-vitreal injections are Rx mainstays

Question 46

What do you look for on fundoscopy in diabetic retinopathy?

Answer 46

- Micro-aneursyms - Venous beading - Intra-retinal vascular abnormalities - Neovascularisation - Vitreous haemorrhage

Question 47

What are some causes of unilateral vs bilateral optic disc swelling

Answer 47

Bilateral - any pathology that raises the ICP Unilateral: - Arteritic Anterior Ischaemic Optic Neuropathy (AION) - Non-Arteritic Anterior Ischaemic Optic Neuropathy (NAION) - Inflammation - optic neuritis - Tumour compressing the orbital - Infection