Visual Loss and Blindness

Question 1

What are some causes of sudden vision loss?

Answer 1

Retinal vein/artery occlusion, vitreous haemorrhage, retinal detachment, closed angle glaucoma, optic neuritis, stroke, wet type age related macular degeneration

Question 2

What are the symptoms of central artery occlusion?

Answer 2

Painless sudden visual loss, relative afferent pupil defect, pale oedematous retina, thread-like retinal vessels

Question 3

What are some causes of retinal artery occlusion?

Answer 3

Carotid artery disease, emboli form heart (rare)

Question 4

Can branches of the retinal artery/vein become occluded?

Answer 4

Yes = also cause sudden visual loss

Question 5

What is amaurosis fugax?

Answer 5

Transient central artery occlusion = urgent referral to stroke clinic

Question 6

What are the symptoms of amaurosis fugax?

Answer 6

Transient painless visual loss = lasts 5 mins with full recovery, “like curtain coming down”
No abnormal signs on examination

Question 7

What are some associations of central vein occlusion?

Answer 7

Endothelial damage (diabetes), abnormal blood flow (hypertension), hypercoagulable state (cancer)

Question 8

What are the symptoms of central vein occlusion?

Answer 8

Sudden visual loss (variable), retinal haemorrhage, dilated tortuous vein, disc and macular swelling

Question 9

What causes ischaemic optic neuropathy?

Answer 9

Occlusion of the optic nerve head circulation = posterior ciliary arteries become occluded causing ischaemia

Question 10

What is an association of ischaemic optic neuropathy?

Answer 10

Giant cell arteritis = medium/large sized arteries are inflamed, lumen of artery becomes occluded due to gross thickening of artery wall

Question 11

What is needed to prevent blindness due to ischaemic optic neuropathy?

Answer 11

Prompt diagnosis and immediate treatment

Question 12

What are the symptoms of ischaemic optic neuropathy?

Answer 12

Sudden severe visual loss, irreversible blindness, swollen optic nerve

Question 13

What are some symptoms of giant cell arteritis?

Answer 13

Temporal headache, jaw claudication, scalp tenderness, tender/enlarged scalp arteries, amaurosis fugax, malaise

Question 14

What are some causes of abnormal vessels?

Answer 14

Retinal ischaemia in diabetes, retinal vein occlusion causes abnormal fragile new blood vessels to form

Question 15

What is a vitreous haemorrhage?

Answer 15

Haemorrhage of blood into areas in and around the vitreous humour = located between lens and retina

Question 16

What are the symptoms of vitreous haemorrhage?

Answer 16

Sudden loss of vision, haemorrhage, loss of red reflex,

Question 17

What are the symptoms of retinal detachment?

Answer 17

Painless sudden loss of vision, sudden onset of flashes/floaters, relative afferent pupil defect, tear seen on ophthalmoscopy

Question 18

Why is there sudden onset of flashes/floaters in retinal detachment?

Answer 18

Due to mechanical separation of sensory retina from the retinal pigment epithelium

Question 19

What is the most common cause of blindness in the west in patients > 65?

Answer 19

Age related macular degeneration

Question 20

What are some risk factors for age related macular degeneration?

Answer 20

Increasing age, smoking, positive family history, poor nutrition

Question 21

What are the two kinds of age related macular degeneration?

Answer 21

Wet and dry

Question 22

What occurs in wet type macular degeneration?

Answer 22

New blood vessels grow under retina = leakage causes build up of blood and eventual scarring

Question 23

What are the symptoms of wet type macular degeneration?

Answer 23

Rapid sudden central visual loss, distortion, haemorrhage/exudate

Question 24

What is glaucoma?

Answer 24

Progressive optic neuropathy = results in optic nerve damage and visual loss

Question 25

What occurs in closed angle glaucoma?

Answer 25

Aqueous humour encounters increased resistance through iris/lens channel

Question 26

What does the increased pressure gradient in closed angle glaucoma cause?

Answer 26

Causes peripheral iris to blow out = obstructs trabecular meshwork

Question 27

How is blindness prevented in closed angle glaucoma?

Answer 27

Need to lower intra-ocular pressure with drops/oral medication = acute onset is ophthalmic emergency

Question 28

What are the symptoms of closed angle glaucoma?

Answer 28

Painful red eye, sudden visual loss, headache, nausea, vomiting, cloudy cornea, dilated pupil

Question 29

What are some features of gradual visual loss?

Answer 29

Usually bilateral, often asymmetrical, may present early with reduced visual acuity or late with decreased field

Question 30

What are the causes of gradual visual loss?

Answer 30

Cataract, dry type age related macular degeneration, open angle glaucoma, diabetic retinopathy

Question 31

What are cataracts?

Answer 31

Cloudiness of the lens

Question 32

What causes cataracts?

Answer 32

Abnormal changes in lens proteins (crystallins) result in their chemical/structural alteration = leads to loss of transparency

Question 33

What is the number one cause of preventable blindness worldwide?

Answer 33

Cataracts

Question 34

What are some associations of cataracts?

Answer 34

Age, congenital, trauma, diabetes, steroids

Question 35

What are the different types of cataracts?

Answer 35

Nuclear, subcapsular, Christmas tree (polychromatic)

Question 36

What are some symptoms of cataracts?

Answer 36

Gradual decline in vision (hazy/blurred) that can't be corrected with glasses, may get glare (disabling at night when driving)

Question 37

What is the management for cataracts?

Answer 37

Surgical removal with intra-ocular lens implant if patient is symptomatic

Question 38

What are the symptoms of dry type age related macular degeneration?

Answer 38

Gradual decline in vision, central vision missing (scotoma), build up of waste products below RPE (Drusen sign), atrophic patches of retina

Question 39

What is the treatment for dry type age related macular degeneration?

Answer 39

Supportive = low vision aids (e.g magnifiers)

Question 40

What is the main complaint in refractive errors?

Answer 40

Eye can't focus on image = need glasses to correct

Question 41

What are the types of refractive errors in the eye?

Answer 41

``` Myopia = short sighted Hypermetropia = long sighted Astigmatism = usually irregular corneal curvature Presbyopia = loss of accommodation with ageing ```

Question 42

What is strange about open angle glaucomas?

Answer 42

They often have no symptoms

Question 43

What are some signs of an open angle glaucoma?

Answer 43

Cupped disc, visual field defect, may have high intra-ocular pressure