9 - Head & Neck - The Eye Flashcards Preview

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Flashcards in 9 - Head & Neck - The Eye Deck (30):
1

Which bones form the orbit?

- Sphenoid bone
- Ethmoid bone
- Frontal bone
- Lacrimal bone
- Maxillary bone
- Zygomatic bone

2

List the boundaries of the orbit:

Apex = Optic canal
Roof = Frontal + Sphenoid
Floor = Maxillary + Zygomatic
Lateral = Zygomatic + Sphenoid
Medial = Lacrimal + Ethmoid + Maxillary + Sphenoid

3

Which wall of the orbit is the weakest?

Base of orbit

4

Name the tissue of the eye to which the extra-ocular muscles attach to:

Sclera

5

Why does the eye appear red if patient has conjunctivitis? Why does conjunctivitis not affect the iris or pupil?

- Blood vessels in the conjunctivae dilate due to inflammation
- Conjunctivae covers sclera up to the cornea (does not cover pupil/iris)

6

Which structures of the eye are avascular? How do they recieve nutrients?

- Lens
- Cornea

via Aqueous humour

7

Name the tissues which form the outer tough layer of the eyeball:

- Sclera
- Conjunctiva

8

Name the tissues which form the middle layer of the eyeball:

- Choroid
- Ciliary body
- Iris

9

Which structure makes up the inner layer of the eyeball?

Retina

10

Which layer of the eyeball contains a rich network of blood vessels?

Middle layer (mainly in choroid)

11

Name the 3 chambers of the eyeball, and the fluid which fills each:

1) Anterior chamber - Aqueous humour
2) Posterior chamber - Aqueous humour
3) Vitreous chamber - Vitreous humour

12

How does the anterior chamber of the eye communicate with the posterior chamber?

Through the pupil

13

Which structures of the eye secrete aqueous humour?

- Ciliary body
- Ciliary processes

14

What are the roles of the ciliary body?

- Controls thickness and focus of lens
- Varies opening of trabeculae meshwork
- Secretes aqueous humour

15

Describe the drainage of aqueous humour into the venous system:

- Through Irido-corneal angle
- Into canal of Schlemm via trabecular meshwork

16

Name the 3 canals which open into the orbit, and which bone they lie in:

- Superior orbital fissure
- Inferior orbital fissure
- Optic canal

= Sphenoid bone

17

Which structures run in the optic canal?

- Optic nerve
- Ophthalmic artery

18

Which structures run in the superior orbital fissure?

- Oculomotor nerve (sup. + inf. branches)
- Trochlear nerve
- Abducens nerve
- Ophthalmic nerve (frontal, lacrimal + nasociliary branches)
- Superior ophthalmic vein

19

Which structure runs in the inferior orbital fissure?

- Inferior ophthalmic vein

20

What is a 'blow-out fracture'?

Fracture of orbit, usually medial wall + floor

21

What is Reiter's syndrome?

Conjunctivitis, arthritis + urethritis
- Autoimmune reactive arthritis due to bacterial infection

22

What is the classical presentation of an Oculomotor nerve lesion?

- Ptosis
- Fully dilated pupil
- 'Down-and-out' eye

23

Why may someone with a facial nerve palsy have to consistently dab eye due to constant weeping?

Paralysis of orbicularis oculi
= Inferior eyelid pulls away, exposing cornea
= Constant irritation
= Increased lacrimal secretion

24

What is cataracts? Who does it commonly affect?

Opacification of the lens
= reduced vision
= reduced acuity
= reduced contrast sensitivity

Diabetics, smokers, elderly

25

What is Presbyopia?

The natural long-sightedness occurring with age, due to loss of elasticity of lens

26

How does retinal detachment present? What causes these symptoms?

Blurring of vision, black dots/streaks, sudden flashes of light

Retina detaches from choroid (which contains blood supply), leading to avascular necrosis of retina.

27

Name the most common type of glaucoma:

Open-angle glaucoma

28

What is open-angle glaucoma?

Increased intra-ocular pressure due to blockage within trabecular meshwork of eye = damaged optic nerve
Develops slowly and painlessly.
Signs = optic disc cupping, loss of visual field

29

What is the treatment for open-angle glaucoma?

- Eyedrops to reduce aqueous humour production: beta-blockers ie Timolol

- Surgery (trabeculectomy)

30

What is closed-angle glaucoma?

Rapid increase in intracranial pressure due to narrowing of irido-corneal angle