Clinical Pathologies of the Eye, Orbit, and Associated Stuctures

Question 1

What is the most common orbital wall fracture?

Answer 1

The floor (inferior wall)

Question 2

How can the floor of the orbit fracture?

Answer 2

Following direct impact to the front of the eye

Question 3

What is a fracture of the orbital floor known as?

Answer 3

An orbital blow out fracture

Question 4

What is conjunctivitis?

Answer 4

When the conjunctivae becomes inflamed

Question 5

What happens to the eye in conjunctivitis?

Answer 5

Blood vessels dilate and the eye appears red

Question 6

What causes glaucoma?

Answer 6

Increased intra-ocular pressure due to the obstruction of drainage of aqueous humour

Question 7

What are the types of glaucoma?

Answer 7

• Open-angle glaucoma
• Closed-angle glaucoma

Question 8

What is the main risk factor for glaucoma?

Answer 8

Increasing age

Question 9

What happens to glaucoma if left untreated?

Answer 9

Leads to irreversible damage and death of the optic nerve, causing impairment of vision and blindness

Question 10

What is an open angle glaucoma caused by?

Answer 10

Blockage within trabecular meshwork, which drains into the canal of Schlemm

Question 11

Describe the development of open-angle glaucoma

Answer 11

Develops painlessly and insidiously over time

Question 12

What is the result of glaucoma developing painlessly and insidiously over time?

Answer 12

Can be difficult to pick up

Question 13

What does treatment of open-angle glaucoma involve?

Answer 13

Topical medications (eye drops) that reduce the production of aqueous humour and/or increase its drainage

Question 14

What medications are used in the treatment of open-angle glaucoma?

Answer 14

• ß-blockers
• Timolol

Question 15

What may be required if the treatments for open-angle glaucoma fail?

Answer 15

Surgery; Trabeculectomy

Question 16

When are signs of glaucoma screened for?

Answer 16

Opticians screen for signs during routine eye tests

Question 17

How can a rise in intra-ocular pressure be detected?

Answer 17

By directing a brief puff of air against the front of the eye (cornea)

Question 18

What signs of glaucoma can be detected on eye examination?

Answer 18

• Cupping of the optic disc
• Visual field loss

Question 19

What is a closed-angle glaucoma?

Answer 19

When the irido-corneal angle is narrowed by the peripheral edge of the iris

Question 20

What does closed-angle glaucoma?

Answer 20

Rapid rise in intra-ocular pressure

Question 21

What is more common, open or closed angle glaucoma?

Answer 21

Open

Question 22

Who is at most risk of closed angle glaucoma?

Answer 22

Long-sighted middle aged, or elderly people

Question 23

What is true of the acute presentation of a closed-angle glaucoma?

Answer 23

It is an opthalmic emergency

Question 24

Why is the acute presentation of a closed-angle glaucoma an opthalmic emergency?

Answer 24

It requires rapid recognition and management, as irreversible sight loss can occur within a few hours

Question 25

How does a closed-angle glaucoma present?

Answer 25

* Sudden onset of a painful red eye * Blurred vision or halos around objects * Fixed or sluggish semi-dilated, often irregular, oval-shaped pupil * Nausea and vomiting

Question 26

What does the management of closed-angle glaucoma involve?

Answer 26

* Instilling muscarinic eye drops * Strong analgesia * Drugs to reduce intra-ocular pressure ## Footnote *While awaiting an emergency opthalmology opinion*

Question 27

What muscarinic eye drops can be used in closed-angle glaucoma?

Answer 27

Pilocarpine

Question 28

When can cataracts occur?

Answer 28

As we age

Question 29

What causes cataracts?

Answer 29

Degradation of proteins in the lens can cause it to become clouded and less transparent

Question 30

How quickly do cataracts develop?

Answer 30

Gradually develop

Question 31

What can cataracts cause?

Answer 31

Significant visual impairment

Question 32

How can cataracts be treated?

Answer 32

Surgery

Question 33

What is retinal detatchment?

Answer 33

When the retina begins to pull away from the blood vessels that supply it with oxygen and nutrients

Question 34

What can cause retinal detatchment?

Answer 34

Due to age or trauma

Question 35

Why can retinal detachment occur?

Answer 35

Occurs because sclera and choroid develop together, but the retina doesn't, so it's the first thing to tear off

Question 36

What can happen if a retinal detachment is not caught early enough?

Answer 36

Can cause blindness

Question 37

Why can retinal detachment cause blindness if not caught early enough?

Answer 37

Due to loss of blood supply to retina

Question 38

What does a lesion of the oculomotor nerve affect?

Answer 38

Most of the extraocular muscles

Question 39

What happens to the affected eye in an oculomotor nerve palsy?

Answer 39

The affected eye is displaced laterally and inferiorly

Question 40

What muscle displaces the affected eye laterally in oculomotor nerve palsies?

Answer 40

Lateral rectus

Question 41

What muscle displaces the affected eye inferiorly in oculomotor nerve palsies?

Answer 41

Superior oblique

Question 42

What does a lesion of the trochlear nerve palsy affect?

Answer 42

Will paralyse superior oblique muscle

Question 43

How does a trochlear nerve palsy present?

Answer 43

No obvious affect on the resting orientation of the eyeball, but patient will complain of diplopia and may develop a head tilt away from the site of lesion

Question 44

What does a lesion of the abducens nerve cause?

Answer 44

Will paralyse the lateral rectus muscle

Question 45

What happens to the affected eye in trochlear nerve palsies?

Answer 45

Affected eye will be adducted by the resting tone of the medial rectus

Question 46

What is a style?

Answer 46

A small, painful cyst on the inside or outside of the eyelid

Question 47

What is a stye usually caused by?

Answer 47

A bacterial infection

Question 48

What does a stye usually affect?

Answer 48

One eye

Question 49

Does a stye affect vision?

Answer 49

No

Question 50

What are the main symptoms of a stye?

Answer 50

* Painful yellow lump on or in the eyelid * Redness of eye or eyelid * A watery eye, *in some cases*

Question 51

What often happens with styes?

Answer 51

They get better withour treatment

Question 52

What is a Meibomian cyst, or Chalazion?

Answer 52

A common condition caused by a blockage of a gland in the eyelid

Question 53

Can Meibomian cysts get infected?

Answer 53

Rarely

Question 54

How can Meibomian cysts be treated?

Answer 54

With injection, or removed with small operation

Question 55

What are the symptoms of a Meibomian cyst?

Answer 55

* Small lump on eyelid * Mild pain or irritation

Question 56

What is papillodema?

Answer 56

An optic disc swelling that is caused by increased intracranial pressure

Question 57

Give 5 examples of things that can cause raised intracranial pressure

Answer 57

* Brain tumour * Hypotonia * Tumours of the frontal lobe * Glaucoma * Local lesion