Retinal Disorders Flashcards Preview

Systems: Neurology AB > Retinal Disorders > Flashcards

Flashcards in Retinal Disorders Deck (48)
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1
Q

What examinations of the eyes can be carried out?

A
  • Direct ophthalmoscope
  • Indirect ophthalmoscope
  • Fundoscopy
  • Biometry
  • Perimetry
  • Optical coherence tomography
  • Fluorescein angiography
2
Q

What is the inner blood-retinal barrier (retinal capillaries) impermeable to?

A

Fluorescein

3
Q

What is the outer blood-retinal barrier (zonula occludens) impermeable to?

A

Fluorescein

4
Q

What is the choriocapillaries permeable to?

A

Free fluorescein

5
Q

In fluorescein angiography how does the fluorescein bind?

A
  • 85% bound to serum proteins

- 15% unbound free fluorescein

6
Q

What type of light excites fluorescein in the blood vessels?

A

Blue light

7
Q

What type of light emerges from the eye during fluorescein angiography?

A

Yellow-green and blue light

8
Q

What type of cells are more prevalent in the fovea?

A

Cone cells

9
Q

What is the blind spot?

A

The area where there is no photoreceptors

10
Q

Electrophysiology

A

A series of investigations recording electrical signals from the eye, optic nerve and brain in response to visual stimuli

11
Q

Electroretinogram

A

-Measures retinal function

Records action potentials within the retina (a waves from photoreceptors and b waves from Muller’s cells)

12
Q

Electro-oculogram

A
  • Measures function of RPE and photoreceptors
  • Measures resting potential difference between the RPE and photoreceptors
  • Maximum potential difference in light adapted eye
  • Minimum potential difference in dark adapted eye
  • Arden ration 1.85
13
Q

Visually Evoked Potentials

A
  • Records optic nerve function

- Measures electrical activity in the visual cortex in response to either a flashing light or a checker board pattern

14
Q

What can visually evoked potentials reveal?

A
Reduced amplitude
-Reduced cell number
-Ischaemic/traumatic optic neuropathy
Latency
-Reduced cell function
-Optic neuritis
15
Q

What investigations should be carried out to diagnose a retinal pathology?

A
  • Visual acuity, visual fields, colour vision, RAPD
  • Fundoscopy
  • Fluorescein angiography
  • Optical coherence tomography
  • Electrophysiology
16
Q

What can cause sudden painless loss of vision?

A
  • Central retinal vein occlusion
  • Central retinal artery occlusion
  • Ischaemic optic neuropathy
  • Stroke
  • Vitreous haemorrhage
  • Retinal detachment
  • Sudden discovery of pre-existing unilateral LoV
17
Q

What are the common causes of central retinal vein occlusion?

A

Hypertension

  • Glaucoma
  • Hyper viscosity
  • Inflammation
18
Q

What are the common causes of central retinal artery occlusion?

A
  • Emboli (carotids/heart)

- Inflammation

19
Q

What are the 2 types of ischaemic optic neuropathy?

A
  • Arteritic (AION)

- Non-arteritic (NAION)

20
Q

What are the symptoms of giant cell arteritis?

A
  • Headache
  • Scalp tenderness
  • Jaw claudication
  • Neck pain
  • Nausea/anorexia
  • Loss of vision
21
Q

What investigative result may indicate giant cell arteritis?

A
  • Raised inflammatory markers

- Positive temporal artery biopsy

22
Q

What are the signs and symptoms of optic neuritis?

A
  • Pain on eye movements
  • Reduced vision
  • Red desaturation
  • Central scotoma
  • Relative afferent pupil defect
  • Swollen optic disc
23
Q

What can cause gradual painless loss of vision?

A
  • Cataract
  • Refractive error
  • Age-related macular degeneration
  • Open-angle glaucoma
  • Diabetic retinopathy
  • Hypertensive dystrophies
  • Inherited retinal dystrophies
  • Drug-induced retinopathy
24
Q

What does age-related macular degeneration present with?

A

Progressive loss of central vision

25
Q

What is the prevalence of age-related macular degeneration?

A

Common

  • 10% >65
  • 30% >75
26
Q

What are the risk factors for age-related macular degeneration?

A
  • Age
  • Smoking
  • Poor diet
27
Q

What are the 2 types of age-related macular degeneration?

A
  • Dry type

- Wet type

28
Q

How does dry type age-related macular degeneration present?

A
  • Atrophy

- Drusen

29
Q

What does diabetic retinopathy present with?

A
  • Cotton wool spots
  • Exudates
  • Vascular anomalies
  • Maculopathy
30
Q

Retinal dystrophies

A

Series of inherited conditions affecting photoreceptor function leading to progressive loss of vision

31
Q

Give examples of photoreceptor dystrophies (ERG reduced)

A
  • Retinitis pigmentosa
  • Cone dystrophy
  • Leber’s congenital amaurosis
32
Q

Give examples of RPE-dystrophies (EOG reduced)

A
  • Best’s vitelliform macular dystrophy
  • Stargardt macular dystrophy
  • Sorsby macular dystrophy
  • North Carolina macular dystrophy
33
Q

Give examples of choroidal dystrophies.

A
  • Choroideraemia

- Gyrate atrophy

34
Q

Give examples of vitreoretinal dystrophie.

A
  • Stickler syndrome

- Congenital retinoschisis

35
Q

What does retinitis pigmentosa predominantly affect?

A

Rod cells

36
Q

What are the different paths of inheritance of retinitis pigmentosa?

A
  • Sporadic
  • Dominant
  • Recessive
  • X linked recessive
  • Unknown
37
Q

What are the different paths of inheritance for cone dystrophy?

A
  • Sporadic
  • Dominant
  • X-linked recessive
38
Q

How does photopic ERG present in cone dystrophy?

A

Reduced

39
Q

What is the scotopic of cone dystrophy?

A

Normal

40
Q

What is the inheritance of Best’s vitelliform macular dystrophy?

A

Dominant

41
Q

What is the inheritance of Stargardt macular dystrophy?

A

Recessive

42
Q

What is the inheritance of Sorsby macular dystrophy?

A

Dominant

43
Q

What is the inheritance of North Carolina macular dystrophy?

A

Dominant

44
Q

What is the inheritance of Choroideraemia?

A

X-linked recessive

45
Q

What is the inheritance of gyrate atrophy?

A

Recessive

46
Q

Give examples of drugs that can induce retinopathy?

A
  • Antimalarials
  • Phenothiazines
  • Tamoxifen
47
Q

Give examples of other acquired maculopathies?

A
  • Central serous retinopathy
  • Idiopathic macular hole
  • Epiretinal membrane
  • Cystoid macular oedema
  • Myopic maculopathy
  • Choroidal folds
  • Angioid streaks
48
Q

How does gene therapy work?

A
  • Defective or missing gene
  • Uses viral vector to insert replacement gene into host DNA
  • Replacement gene synthesises protein