Unit 2 - The fundus Flashcards

1
Q

What are the components of the fundus?

A

Retina, retinal pigmented epithelium, tapetum, chroid, sclera, and optic nerve head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How do you evaluate the fundus?

A

Direct/indirect ophthalmoscopy

Ultrasonography

Electroretinogram

Advanced ocular imaging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the retinal vascular patterns?

A

Holangiotic, paurangiotic, merangiotic, and anangiotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the holangiotic retinal vascular pattern.

A

Vessels go throughout the fundus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What species have the holangiotic retinal vascular pattern?

A

Dog, cat, and rodent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the paurangiotic retinal vascular pattern.

A

Short vessels directly adjacent to the optic nerve head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What species have paurangiotic retinal vascular patterns?

A

Horse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the merangiotic retinal vascular pattern.

A

Vessels are in a broad horizontal band

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What species have merangiotic retinal vascular patterns?

A

Rabbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the anangiotic retinal vascular pattern.

A

No blood vessels are in the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What species have anangiotic retinal vascular patterns?

A

Birds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the normal feline fundus look like?

A

Dark, small, round optic nerve - not myelinated

3 major venules leave the disk edge with 3 major arterioles

If the tapetum is present, it is usually yellow or green in color +/- pigment in the choroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the normal canine fundus look like?

A

Usually 3 or 4 major venules that cross the disc edge

Forms a circle on the optic disc surface

Up to 20 arterioles

The tapetum can be any color

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the canine optic disc typically look like?

A

Variable amount of myelin

Pale pink in color

Physiological pit +/- pigmented ring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the normal horse fundus look like?

A

30-60 small blood vessels extend a short distance from the disk edge

Oval, pink, optic disc in the non-tapetum

‘Stars of winslow’ - end on capillaries in tapetum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

T/F: The pecten is a normal part of the rabbit fundus.

A

False - it is a normal part of the bird fundus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the clinical signs of fundic disease?

A

Vision-loss (day versus night)

Dilated, poorly/non-responsive pupils

Decreased/absent dazzle reflex

Changed tapetal reflectivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which of these is normal?

A

A - notice the hyperreflextive ring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which of the following is representative of hyporeflectivity? Hyperreflectivity?

A

Hyporeflectivity - B

Hyperreflectivity - C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When a fundus is hyporeflective, what is the problem layer?

What is wrong with it?

A

Retina - edematous/infilatrated retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When a fundus is hyperreflective, what is the problem layer?

What is wrong with it?

A

Retina - atrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does vascular attenuation look like?

A

There should be tertiary branching and it should reach the periphery of the fundus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What disorders is vascular attenuation seen in?

A

Retinal degeneration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What vascular change is present in this photo?

A

Lipemia retinalis - hyperlipidemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What vascular change is present in this photo?

A

Engorged vessels - hyperviscosity syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What vascular change is present in this photo?

A

Perivascular cuffing - inflammatory disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What vascular changes are present in these photos?

A

Retinal hemorrhages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the differential diagnoses for retinal hemorrhages?

A

Systemic hypertension

Coagulopathies

Chorioretinitis

Diabetic retinopathy (dogs)

Vasculitis

Severe anemia

Hyperviscosity

Trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What lesion is present in this photo?

A

Multifocal retinal dysplasia/folds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What lesion is present in this photo?

A

Multifocal retinal dysplasia/folds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What lesion is present in this photo?

A

Geographic retinal dysplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is Collie Eye anomaly?

A

A hereditary eye disease in collies and other herding breeds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What syndrome does Collie eye anomaly cause?

A

Choroidal hypoplasia

Tortuous vessels

Optic nerve/peripapillary colobomas +/- retinal detachment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is a coloboma?

A

Congenital defect/absence of tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is optic nerve hypoplasia?

A

When there is a small optic nerve head with visual deficits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What breed is predisposed to optic nerve hypoplasia?

A

Miniature poodle

37
Q

What is micropapilla?

A

A small optic nerve heat but visual

38
Q

T/F: Progressive retinal atrophy is an acquired disease.

A

False - it is hereditary

39
Q

What is progressive retinal atrophy?

A

The progressive loss of rods then cones

40
Q

T/F: Progressive retinal atrophy is irreversible and there is no treatment.

A

true

41
Q

How is progressive retinal atrophy prevented?

A

Genetic testing - avoid breeding

42
Q

How is progressive retinal atrophy diagnosed?

A

History, fundic exam, genetic testing, +/- ERG

43
Q

T/F: Cats don’t get progressive retinal atrophy.

A

False - they do, but it is less common

44
Q

What signs on a fundic exam are indicative of progressive retinal atrophy?

A

Tapetal hyperreflectivity

Pale ONH

Blood vessel attenuation

45
Q

How do patients with hypertensive chorioretinopathy typically present?

A

They often present for acute blindness

46
Q

What ocular signs are associated with hypertensive chorioretinopathy?

A

Dilated, poorly to unresponsive pupils

Retinal detachment with retinal and vitreal hemorrhages

47
Q

Do dogs or cats get hypertensive chorioretinopathy more?

A

Cats >> dogs

48
Q

How is hypertensive chorioretinopathy treated?

A

Identify and treat the underling cauase

Calcium channel blockers - amlodipine primary therapy +/- ACE -inhibitor

49
Q

T/F: Hypertensive chorioretinopathy patients can regain vision.

A

True - if the retina can reattach as soon as possible

50
Q

What are the most common differentials for retinal detachment?

A

Hypertensive chorioretinopathy (esp cats)

Chorioretinitis

Congenital lesions

Post-intraocular surgery

51
Q

How do you diagnose retinal detachment if you can’t visualize it?

A

Ocular ultrasound

52
Q

What does retinal detachment look like on ocular ultrasound?

A

Classic seagull wing appearance

Usually remains attached at ora ciliaris and optic nerve

Hyperechoic lines traced to optic nerve

53
Q

What is the cause of taurine retinopathy?

A

Chronic taurine deficiency in cats

54
Q

What is taurine retionopathy?

A

Feline central retinal degeneration

55
Q

How is taurine retinopathy confirmed?

A

Measure plasma taurine levels

56
Q

T/F: Correction of a cats taurine deficiency will prevent progression of taurine retinopathy and will reverse it.

A

False - it will prevent progression, but won’t reverse it

57
Q

In what species is enrofloxacin retinal toxicity found?

A

Cats

58
Q

What dose of enrofloxacin results in retinal toxicity?

A

>5 mg/kg PO SID

59
Q

What is the first sign of enrofloxacin retinal toxicity?

A

Dilated pupils due to retinal degeneration

60
Q

If you have a patient that you suspect has enrofloxacin retinal toxicity, what should you do first?

A

Place them in the dark - light is what is associated with the damage

61
Q

What should be used to treat enrofloxacin retinal toxicity?

A

Pradofloxacin

62
Q

What species are most susceptible to ivermectin toxicity? Why?

A

Dogs are more susceptible to cats because they are scavengers and eat what they find

63
Q

What dogs are especially susceptible to ivermectin toxicity?

A

Neonates and those with the MDR1 mutation

64
Q

What clinical signs are associated with ivermectin toxicity?

A

Acute blindness, pupil changes, neurologic signs

65
Q

What fundic changes are associated with ivermectin toxicity?

A

Retinal folds and edema

66
Q

How is ivermectin toxicity treated?

A

Supportive care +/- lipid emulsion

67
Q

T/F: Blindness due to ivermectin toxicity is usually transient and will reverse once the toxin leaves the system.

A

True

68
Q

What can cause chorioretinitis (non-specific)?

A

Infectious, neoplastic, and immune-mediated/inflammatory causes

69
Q

How is chorioretinitiis treated?

A

Treat underlying cause Symptomatic treatment of the chorioretinal inflammation

70
Q

Why don’t you want to use anti-inflammatory eye drops to treat chorioretinitis?

A

The drops won’t reach the back of the eye

71
Q

What does active chorioretinitis look like?

A

Indistinct borders and hyporeflective

72
Q

What does inactive chorioretinitis look like?

A

Hyperreflective, well-demarcated, pigmented centers

73
Q

What does SARDS stand for?

A

Sudden acquired retinal degeneration syndrome

74
Q

How do dogs with SARDS present?

A

Acute onset of blindness that lasts days to weeks +/- PU/PD, polyphagia, weight gain

75
Q

What are the ‘3 F’s’ that are characteristic of a patient with SARDS?

A

Fat, five, female

76
Q

What bloodwork changes will you find in a patient with SARDS?

A

Hyperadrenocorticism

77
Q

What ocular findings are consistent with a SARDS patient?

A

Normal fundus initially that degenerates over time

78
Q

How is SARDS diagnosed?

A

Electroretinogram - no electrical function/flatline

79
Q

T/F: Optic neuritis is a clinical symptom rather than a single disease.

A

True

80
Q

Optic neuritis is usually unilateral or bilateral?

A

bilateral

81
Q

How do patients with optic neuritis present?

A

Pupils are fixed and dilated

82
Q

What is seen on a fundic exam in patients with optic neuritis?

A

ONH is hyperemic and elevated with hemorrhages on the surface

The ONH may appear normal if retrobulbar nerve is affected

83
Q

What are the causes of optic neuritis?

A

Infectious diseases

Inflammatory/immune-mediated - GME

Neoplastic

Trauma

Idiopathic

84
Q

How is optic neuritis diagnosed?

A

Typical clinical signs, normal ERG, and MRI

85
Q

How is optic neuritis treated?

A

Treat underlying cause and systemic anti-inflammatory drugs

86
Q

What is the prognosis for vision in optic neuritis patients?

A

Variable - guarded to poor

87
Q

What are the ddx for optic nerve atrophy?

A

Glaucoma, PRA, orbital disease, optic neuritis, trauma (esp. horses)

88
Q

What happens to the optic disk in patients with optic nerve atrophy?

A

The disc loses myelin and appears pale - may look like a cats eye

89
Q

What clinical sign is associated with optic nerve atrophy?

A

blindness