2.5: Visual Loss and Blindness Flashcards Preview

Ophthalmology > 2.5: Visual Loss and Blindness > Flashcards

Flashcards in 2.5: Visual Loss and Blindness Deck (65):
1

What are the two types of visual loss?

Gradual Sudden

2

What are four causes of sudden visual loss?

Vascular

Retinal Detachment

Age-Related Macular Degeneration

Closed Angle Glaucoma

3

Describe the arterial supply to the eye?

Internal carotid gives off the ophthalmic artery This has many branches that supply the eye Some of the branches include: - Central Retinal Artery - Posterior Ciliary Artery

4

Describe vascular causes of sudden vision loss?

Occlusion of the retinal circulation

Occlusion of the optic nerve head circulation Haemorrhage from abnormal blood vessels Haemorrhage from normal blood vessels (retinal tear)

5

Describe the blood supply to the retina?

Central retinal artery supplies inner 2/3rd of retina Posterior Ciliary Artery supplies outer 1/3rd of retina

6

Describe occlusion of the retinal circulation? (Where can be occluded?) There are three types

Central Retinal Artery Occlusion - affects all of retina

Branch Retinal Artery Occlusion - affects only the area supplied by the branch

 

Amaurosis Fugax - Transiet central retinal occlusion

7

Describe central retina artery occlusion? - Symptoms

This causes sudden visual loss Profound visual loss (Counting fingers or less)

 

Painless Central artery is end artery (no other supply) so can lead to blindness

8

Signs of central retina artery occlusion?

Relative Afferent Pupil Defect (RAPD) - eyes react differently

 

Pale, oedematous retina with thin, thready vessels

9

Describe what you see? Condition?

Small area in middle of normal retina (supplied by tiny blood vessel) Rest of retina is pale Thin, thready vessels Condition is central retinal artery occlusion

10

What can cause central retinal artery occlusion?

Carotid Artery Disease (Plaques in artery) Emboli from heart (clot/vegetation etc.) Less rare

11

Those who have a central retinal artery occlusion are at risk of developing...?

Stroke Central retinal artery occlusion is a type of mini-stroke and patients who have this are at risk of developing full blown stroke

12

Management of central retinal artery occlusion? - Present very early? - Present later?

Carotid Massage to try move occlusion from central to branch (minimise damage, save sight) Later: - Carotid doppler to establish site of occlusion - Assess and manage risk factors (for further stroke)

13

Describe branch retinal artery occlusion? - What does this look like on examination?

In central, entire retina is affected In branch, only the area supplied by that branch is affected Some vision is unaffected - Only some of the retina is pale on examination

14

Describe amaurosis fugax? - What does this look like on examination? - Treatment?

This is transient central retinal artery occlusion Like a curtain shutting/blind coming down Only lasts for a few minutes - Very little to see on examination - Treatment includes referral to TIA clinic (this is a sign that central occlusion or stroke may occur) and aspirin

15

Another cause of amaurosis fugax? How do you determine the cause?

Migraines Migraines are followed by a headache, amaurosis fugax is not

16

Describe central retinal vein occlusion? Causes?

This is when there is occlusion of the central vein that drains the retina Causes: Virchow's Triad (Hypercoagulable, Abnormal Blood Flow (Stasis) and Endothelial Injury) Raised IOP (Intraocular Pressure)

17

Symptoms of central retinal vein occlusion? Signs?

Sudden visual loss Moderate to severe (less than central artery occlusion)

18

Signs of central retinal vein occlusion?

Retinal Haemorrhages Tortous Veins Disc and Macular Swelling Cotton Wool Spots

19

Treatment of central retinal vein occlusion?

Based on cause (Treat underlying cause) Monitor - New vessels may form which may cause complications and require laser treatment Anti-VGEF to shrink back any new vessels

20

Describe why new vessels form in central retinal vein occlusion? Why do we treat them?

New vessels form to help get round the occlusion These are thin and weak and can bleed/rupture leading to more complications That is why we treat them with laser treatment and anti-VGEF (to prevent the complications)

21

 What do you see? What condition?

Tortous Veins Dark retina (haemorrhage) Central Retinal Vein Occlusion

22

What do you see? What condition?

One tortuous vein One patch of darkness and haemorrhage Branched Retinal Vein Occlusion

23

 What do you see? What condition?

One area of paleness One thready vessel Branched Central Artery Occlusion

24

Describe occlusion of optic head circulation? Describe arterial supply to optic nerve head and its relevance in this condition?

This is also called ischaemic optic neuropathy (ischaemic damage to the optic nerve) This is infarction of the optic nerve head due to obstruction of the posterior ciliary arteries Posterior ciliary arteries are not end arteries so patients may have severe visual loss but not complete

25

What are the two types of ischaemic optic neuropathy?

Arteritic Non-Arteritic

26

Describe the presentation of ischaemic optic neuropathy?

Sudden, profound visual loss with swollen discs

27

Describe arteritic ischaemic optic neuropathy (ION) - How does this occur?

This is damage to the optic nerve due to ischaemia of the optic nerve

Caused by Giant Cell Arteritis (GCA) or temporal arteritis This is inflammation of the medium to large arteries Inflammation blocks the lumen of the arteries Visual loss from ischaemia of optic nerve head

28

Describe the symptoms in arteritic ION

Sudden, vision loss Profound vision loss (counting fingers only or in some cases no perception of light) Temporal Headaches Jaw pain when chewing Scalp tenderness Enlarged scalp arteries Malaise

29

Describe the visual loss in arteritic ischaemic optic neuropathy

Sudden vision loss Profound vision loss - can be counting fingers or no perception of light Irreversible blindness Important to catch early to prevent both eyes becoming blind

30

What may help diagnosis of arteritic ischaemic optic neuropathy

Temporal Artery Biopsy

Shows up if there is Giant Cell Arteritis Disease present

31

Treatment in arteritic ischaemic optic neuropathy

Quick treatment High dose steroids to save the other eye from going blind

32

Complications of arteritic ION?

Blindness - one eye or both Can lead to death (if the arteritis affects coronary arteries)

33

One of the causes of sudden visual loss is haemorrhage - what the two types?

Haemorrhage of abnormal blood vessels Haemorrhage of normal blood vessels

34

Describe haemorrhage of abnormal blood vessels?

In ischaemia, the body responds by the formation of new vessels - often in the wrong place These vessels are very fragile and can rupture easily Can bleed and cause damage to the retina

35

Describe haemorrhage of normal blood vessels?

Retinal tears in areas that are supplied by blood vessels can lead to bleeding

36

Where does haemorrhage of the eye usually occur into?

The vitreous cavity

37

Describe the signs and symptoms of vitreous haemorrhage?

Symptoms: - Loss of vision - Floaters Signs: - Loss of red reflex - Haemorrhage on fundoscopy

38

Treatment/Management of vitreous haemorrhage?

Identify the cause Vitrectomy for non-resolving cases

39

Describe retinal detachment?

This is when the retina detaches from the supporting layer of soft tissue

40

Signs and symptoms of retinal detachment?

Symptoms: - Loss of vision - Sudden onset of flashes and floaters Symptoms: - May have relative afferent pupil defect - May see tear on ophthalmoscopy

41

Treatment/Management of retinal detachment?

Usually surgery

42

What are the two types of age related macular degeneration?

Wet = Sudden onset visual loss Dry = Gradual onset visual loss

43

Describe wet age related macular degeneration?

This is the formation of new blood vessels under the retina Leakage from these blood vessels causes accumulation of fluid and blood This causes scarring of the retina and vision loss

44

Symptoms of wet age related macular degeneration? Signs of wet age related macular degeneration?

Symptoms: Rapid central vision loss Distortion of straight lines (Metamorphosia) Signs: Haemorrhage or exudate

45

Treatment of wet age-related-macular degeneration?

Anti-VGEF Given by intravitreal injection

46

Describe gradual visual loss? When do people present?

Often bilateral Asymmetrical (one side worse) If they have reduced visual acuity --> Presents early If they have reduced visual field --> Presents late

47

Causes of gradual visual loss? Mnemonic for remembering this?

Cataracts Age Related Macular Degeneration (Dry) Refractive Error Diabetic Retinopathy Inherited Disease Glaucoma Access to eye clinic Non Urgent (Cardigan) but really just CARDIG

48

What is cataracts? Causes?

Cloudiness of the lens Very common Can be age related, congenital, traumatic, metabolic (Eg: Diabetes) or drug induced (Steroids) Many different types

49

Management of Cataracts?

Surgical Removal with intra-ocular lens implantation if patient is symptomatic

50

Describe dry age-related macular degeneration?

This is gradual loss of vision Missing of the central vision (Scotoma)

51

What is Scotoma?

This is a partial loss of vision/blind spot in an another wise normal field of vision

52

Symptoms of dry age related macular degeneration?

Symptoms: Loss of vision Loss of central vision (Scotoma) Signs: Drusen (Build up of lipid deposits) Atrophic Patches of retina

53

Treatment for dry age related macular degeneration?

No treatment available Supportive visual aids eg: Magnifiers

54

What is refractive error?

This is when the eye is unable to clearly focus an image

55

What is myopia?

Being short sighted Eye brings the light into focus too early

56

What is hypertropia?

Being long sighted Eye doesn't bring the light into focus early enough (focused behind retina)

57

What is astigmatism?

Abnormal curvature of the cornea Causes two focal points of light on the retina instead of one

58

What is Presbyopia?

This is the inability to see up close/read small print Happens to everyone with age

59

Describe the treatment for refractive error?

Glasses

60

What is Glaucoma? Cause?

This is progressive optic neuropathy Progressive damage to optic nerve leading to progressive vision loss Cause of glaucoma is unknown - probably multifactorial. Raised IOP may be a factor

61

What are the types of glaucoma?

Closed angle glaucoma Open angle glaucoma Refers to angle between cornea and iris

62

Describe open angle glaucoma? Signs? Symptoms?

This is loss of peripheral vision Often picked up in screening - people don't notice it themselves (No symptoms) Signs: - Cupped disc - Visual field defect - Possible raised IOP

63

Treatment for open angle glaucoma? Follow up?

Aims to preserve vision - Lower IOP using drops Patients require regular monitoring in clinic

64

Describe closed angle glaucoma? Symptoms?

This is a medical emergency Symptoms: - Painful, red eye - Headache - Vision Loss - Nausea and vomiting

65

Treatment for closed angle glaucoma?

Need to lower IOP using drops to prevent patient going blind