D: Vascular 3 Systemic Hypertension - Week 8 Flashcards Preview

OD3 - Clin. Optometry Sem 1 and Preacademic Period > D: Vascular 3 Systemic Hypertension - Week 8 > Flashcards

Flashcards in D: Vascular 3 Systemic Hypertension - Week 8 Deck (47)
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1
Q

Define systemic hypertension. What is considered borderline? What is considered normotensive?

A

Hypertension: BP > 160/95
Borderline: BP = 140/90 - 160/95
Normotensive: BP <140/90

2
Q

In general, what level of diastolic BP is considered too high and worthy of reducing?

A

Any diastolic BP > 100 mmHg

3
Q

List 5 risk factors for hypertension

A
Obesity (bad cholesterol)
Smoking
Family history
Older age
Race: black
4
Q

Define malignant hypertension

A

Diastolic BP > 120mmHg with associated exudative vasculopathy in retina and kidney

5
Q

What percentage of hypertension are secondary? What 2 types of conditions can they be secondary to?

A
5% of cases.
Renal conditions (e.g. nephritis, renal failure, tumour)
Endocrine conditions (e.g. DM, hyperthyroid, cushing)
6
Q

What is pre-eclampsia?

A

A pregnancy complication that generally occurs 20 weeks in where the mother experiences a sudden onset of high blood pressure

7
Q

What can the height of blood pressure predict risk of? (5)

A
coronary artery occlusion
stroke
renal failure
heart failure
peripheral vascular disease
8
Q

How can high blood pressure affect the brain? (2)

A

Damage to cerebral vessels can lead to:
TIA
Stroke

9
Q

How can high blood pressure affect the kidneys? (2)

A

Endarteritic changes in renal bed

Ultimate renal failure from sclerosis

10
Q

How can high blood pressure affect the heart? (2)

A

Left ventricular hypertrophy –> cardiac failure

BP damage to cardiac vessels –> myocardial infarction

11
Q

What proportion of hypertension patients have a normal fundus?

A

1/3rd

12
Q

What are the 2 main effects of hypertension on retinal vessels?

A

Constriction of arterioles

Arteriolar sclerosis

13
Q

Why do arterioles constrict in response to hypertension?

A

to maintain homeostatic blood flow as perfusion pressure drops

A drop in perfusion pressure (as a result of systemic HT) means less blood flow. So the arterioles constrict, increasing TPR, and hence increasing blood flow back to normal values. this process is “autoregulation”

(remember. Occ. perfusion pressure = BP - IOP. Wait what? Shouldn’t it increase then? Come back to this)

14
Q

How does arteriolar sclerosis affect the arterioles and how does this present on a fundus examination? (4)

A

Loss of wall transparency: copper wiring
Lumen narrowing: nicking
Deflection of veins at AV crossings: right angle X-ing
Vein lumen compression: banking

15
Q
Retinopathy grading (Wong &amp; Mitchell):
- No retinopathy?
A

No detectable retinal signs with no systemic associations

16
Q
Retinopathy grading (Wong &amp; Mitchell):
- Mild retinopathy? (description)
A
One or more of: 
Generalised arteriole narrowing
Focal arteriole narrowing
AV nicking
Silver wiring
17
Q
Retinopathy grading (Wong &amp; Mitchell):
- Moderate retinopathy? (description)
A
One or more of:
Haem (blot, dot, flame)
Microaneurysm
CWP
Hard exudates
18
Q
Retinopathy grading (Wong &amp; Mitchell):
- Malignant retinopathy? (description)
A

Moderate retinopathy plus:

- optic disc oedema

19
Q

Retinopathy grading (Wong & Mitchell):

  • Systemic associations:
  • mild retinopathy
  • moderate
  • malignant
A

Mild: Modest association with risk of stroke, coronary heart disease, mortality

Moderate: same but strong + cognitive decline risk

Malignant: strong assoc. with mortality

20
Q

How is focal arteriolar constriction seen on fundus? Where?

A

Alternating zones of passive dilation and spasm

Most readily seen within 1-2DD of disc

21
Q

How common is focal arteriolar constriction in established hypertension?

A

very common

22
Q

What level of sensitivity does focal arteriolar constriction have for systemic hypertension?

A

Good sensitivity and specificity

23
Q

What is venous banking and what causes it? What does this mean in relation to hypertension?

A

Refers to the increased dilation of the vein distal to the AV crossing (aka Bonet Sign) away from the disc. This occurs in response to restriction of venous return and is a reliable guide to the possibility of hypertension.

24
Q

Define distal

A

away from the centre (in the case of distal dilation that means away from ONH)

25
Q

What does venous banking indicate?

A

a significant interruption to vein blood flow

26
Q

What does venous banking increase the risk of? How can this happen

A

thrombus formation and eventual venous occlusion

- this occlusion can occur because the veins endothelium can become sticky, leading to platelet adhesion to the walls

27
Q

How can we bypass the AV crossing?

A

With shunt vessels

28
Q

What causes flame haemorrhages?

A

leakage from superficial capillaries into the NFL

29
Q

What are flame haemorrhages indicative of? (3)

A

Vascular occlusive disease
Diseases specifically affecting blood viscosity
Diseases affecting the integrity of the vessel wall

30
Q

List 6 conditions that can present with flame haemorrhages

A
Glaucoma (esp LTG)
Papillitis
Papilloedema
Following acute PVD
Diabetic retinopathy
Retinal Vein Occlusions
31
Q

What are cotton wool patches?

A

occlusions of minor arterioles/capillaries serving the NFL leading to ischaemia with resultant cloudy swelling of axons (hence they look like cotton wool)

32
Q

How long after vessel infarction does a CWP arise?

A

within 24 hours of infaraction

33
Q

How long do CWPs persist?

A

about 6 weeks

34
Q

As a result of how long they persist, do CWPs represent current or past vascular pathology?

A

Current/acute pathology

35
Q

What is a common cause of CWPs?

A

moderately severe hypertension

36
Q

What is papilloedema?

A

Non-inflammatory bilateral optic nerve head swelling as a result of blockage of axoplasmic transport

37
Q

How does papilloedema present? (5)

A

Visible disc swelling + indistinct margins, and likely also:

  • Venous engorgement, stasis + tortuosity
  • Exudate
  • Flame haemorrhages
  • CWPs
38
Q

List 4 differentials for papilloedema

A

CRVO
AION
Papillitis
Intracranial mass/pseudotumour

39
Q

List 3 important individual signs of hypertension

A

Focal constriction of arterioles (incl. attenuation = straightening + thinning of arterioles)
Banking (bonet sign)
Flame haemorrhages

40
Q

List 5 important signs in hypertension

A
  1. Cotton wool patches
  2. Papilloedema
  3. Vein occlusion
  4. Retinal arteriolar (macroaneurysm)
  5. Non-arteritic AION
41
Q

What is Gunn’s sign?

A

Is where the blood column in the vein appears narrowed just upstream and downstream of the AV crossing (no banking occurring)

42
Q

What is Sallus’ sign?

A

Is where there is a right angle formed at the AV crossing

43
Q

Are gunn’s sign and sallus’ sign indicative of hypertensive retinopathy?

A

No! This isn’t hypertensive retinopathy

44
Q

What 2 choroidal changes occur in hypertension?

A

Elschnig’s spots: (numerous small RPE detachments, little visual significance)
Siegrist’s streaks: (fine pigment lines folowing choroidal vessels which have sclerosed and occluded)

45
Q

Rank from most important to least important the signs used in detecting early hypertension?

A
  1. Focal arteriolar constriction
  2. Vascular occlusions
  3. Banking particularly with shunt vesels
  4. Consider atherosclerosis in other signs
46
Q

What are vascular occlusions evidence by in hypertension? (5)

A
Flame haemorrhages
Lipid exudates
Vein sheathing
Banking
CWPs
47
Q

How can we manage patients with suspicion of hypertension?

A
  1. Refer to GP when signs of recent origin are seen (i.e. haem, CWP, papilloedema, RVO/BRVO, also ophthalm)
    - may indicate need for BP tx or modification
  2. Refer to ophthalm for: (recent vascular occlusion - CVO/BVO, AION, Macroaneurysm)