Anatomy Of The Eye Flashcards

1
Q

Anatomically, how may the eye be divided

A

Into 3 layers:

  1. Fibrous
  2. Vascular
  3. Inner
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2
Q

What does the fibrous layer of the eye contain

A

Sclera and cornea

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3
Q

What is the sclera

A

White structure comprises 85% of fibrous layer, enables attachment of extra-ocular muscles

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4
Q

What is the cornea

A

Transparent structure at the front of the eye

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5
Q

What are the 3 components of the vascular layer

A
  1. Choroid
  2. Ciliary body
  3. Iris
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6
Q

What is the choroid

A

Blood supply to the retina

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7
Q

What is the ciliary body

A

Comprised of the ciliary muscle and ciliary process it controls the shape of the lens and produces aqueous humour

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8
Q

What Is the ciliary muscle

A

Smooth muscle fibres that control shape of the lens

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9
Q

What is the ciliary process

A

Fibres that connect ciliary muscle to lens

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10
Q

What is the iris

A

Circular structure with aperture in the centre that enables light to enter. Smooth muscle controls diameter of the iris.

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11
Q

What forms the inner layer of the eye

A

Retina

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12
Q

What is the retina comprised of

A

Neural Layer

Pigmented Layer

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13
Q

What is the neural layer

A

Contains photoreceptors

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14
Q

What is the pigmented layer

A

Attaches to choroid to help support the neural layer

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15
Q

What is the non-visual retina

A

Where part of the pigmented layer continues anteriorly without neural layer

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16
Q

What is the optic retina

A

Neural and pigmented layer

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17
Q

What part of the retina is seen in ophthalmoscopy

A

Optic retina

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18
Q

What is the centre of the retina called

A

Macula

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19
Q

How does the macular appear on opthalmoscopy

A

Yellow

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20
Q

What is in the centre of the macula

A

Fovea

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21
Q

What does the fovea do

A

High-visual acuity

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22
Q

Where does the optic nerve enter the eye

A

Optic disc

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23
Q

What is not located at the optic disc

A

Photoreceptors

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24
Q

What are the two compartments of the eye

A

anterior and posterior chamber

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25
Q

What is the anterior chamber of the eye

A

from lens to cornea

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26
Q

where is the posterior chamber of the eye

A

iris and ciliary process

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27
Q

what are chambers filled with

A

aqueous humour

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28
Q

what drains aqueous humour

A

canal of schlemm - located in the trabecular meshwork

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29
Q

What is the arterial supply to the eye

A

Ophthalmic artery

30
Q

Where does the ophthalmic artery arise

A

Internal carotid artery

31
Q

What is the most important branch of the ophthalmic artery

A

Central retinal artery

32
Q

What is the venous drainage of the eye

A

Superior and Inferior ophthalmic veins

33
Q

Where do the superior and inferior ophthalmic veins drain

A

Cavernous sinus

34
Q

What are the 3 main presentations for eye conditons

A
  1. Red Eye
  2. Acute visual Loss
  3. Chronic visual loss
35
Q

What 4 conditions may present with a red eye

A
  1. Conjunctivitis
  2. Keratitis
  3. Uveitis
  4. Acute glaucoma
36
Q

What 6 conditions may cause acute loss of vision

A
1. Central retinal artery    
    occlusion
2. Central retinal vein 
    occlusion
3. Retinal detachment 
4. Stroke 
5. GCA 
6. Vitreous Haemorrhage
37
Q

What 4 conditions may cause chronic visual loss

A
  1. Cataracts
  2. Chronic glaucoma
  3. Macular degeneration
  4. Diabetic retinopathy
38
Q

How many bones form the orbit

A

7

39
Q

What two bones form the superior orbit

A

Sphenoid

Frontal

40
Q

What two bones form the lateral orbit

A

Zygomatic

Sphenoid

41
Q

What is a way to remember bones that form medial orbit

A

LEMS

42
Q

What 3 bones form inferior orbit

A

Maxilla
Palatine
Zygomatic

43
Q

What 4 bones form medial orbit

A

Lacrimal
Ethmoidal
Maxillary
Sphenoidal

44
Q

What is the main blood supply to the eye

A

Opthalmic.a

45
Q

Describe origin of opthalmic artery

A

First branch of the internal carotid artery. It passes through the cavernous sinus

46
Q

What are the two groups of branches of opthalmic artery

A

Orbital

Optical

47
Q

What is the role of the orbital group

A

Orbital = Innervates structures in the orbit

48
Q

What is the role of the topical group

A

Optical = innervates the eye and muscles

49
Q

What branch of the ophthalmic nerve innervates the retina

A

Central retinal artery

50
Q

What branch of the ophthalmic nerve innervate the optic disc

A

Short posterior ciliary arteries - which innervate the optic disc as circle of zinn-haller

51
Q

What is the venous drainage of the eye

A

Central retinal vein

52
Q

Where does the central retinal vein drain

A

Cavernous sinus or superior ophthalmic vein

53
Q

Explain visual pathway

A
  • Optic nerve leaves optical canal and passes to optic chiasm
  • At the optic chiasm the peripheral and nasal fields cross over
  • The optic tracts then travel to lateral geniculate nucleus of the thalamus
  • The fibres that supplied superior retina (Inferior visual field) then travel as Meyer’s loop to primary visual cortex
  • The fibres that supplied inferior retina (superior visual field) then travel as Baum’s to primary visual cortex
54
Q

How is visual acuity recorded

A

Numerator =chart distance (6m)

Denominator = lowers line read

55
Q

What does 6/7 on visual acuity mean

A

This person can see at 6m what someone should be able to see at 7m

56
Q

Define miosis

A

Pupil constriction

57
Q

Define mydriasis

A

Pupil dilation

58
Q

What are miotic agents

A

agents that cause pupil constriction

59
Q

Name 3 miotic agents

A
  • M3 receptor agonist
  • a1 antagonist
  • Opioids
60
Q

Name an M3 receptor agonist

A

Pilocarpine

61
Q

Name an a1-antagonist

A

Tamulosin

62
Q

What autonomic NS stimulation causes miosis

A

Parasympathetic

63
Q

What are mydriatics

A

Medications that dilate pupil

64
Q

What are mydriatics also called

A

Cycloplegics

65
Q

Why are mydriatics called cycloplegics

A

As the paralyse ciliary muscles and cause blurring of vision

66
Q

What are 5 mydriatics

A
  1. Anticholinergics
  2. Antipsychotics
  3. Antihistamines
  4. TCAs
  5. A1-receptor agonists
67
Q

What anticholinergic is used in eye exam

A

Tropicamide

68
Q

How long does tropicamide last

A

3h

69
Q

Why do antipsychotics cause pupil dilation

A

M3 receptor antagonists

70
Q

Why may anti-histamines cause mydriasis

A

M3 receptor antagonists

71
Q

Why may anti-depressantscause mydriasis

A

M3 receptor antagonists

72
Q

Name 3 a1-receptor agonists

A

NA
Cocaine
Amphetamines