Session 8- Eye

Question 1

What bone is most likely fractured in an orbital blow out fracture?

Answer 1

Maxilla

Question 2

What are some features of an orbital blow out fracture?

Answer 2

Double vision
Inability to look up

Question 3

Explain a venous route that could lead to infection spreading from the orbit to the brain?

Answer 3

Superior ophthalmic vein travelling through the superior orbital fissure that communicates with the cavernous sinus

Question 4

What plexus does the inferior ophthalmic vein communicate with?

Answer 4

Pterygoid venous plexus

Question 5

How do you determine whether an eye lid lump is a stye or Meibomian cyst?

Answer 5

A Stye is a painful lump on the edge of an eyelid due to the blocking of a sebaceous gland of an eye lash

A Meibomian cyst is a painless lump deeper into the lid, it’s non infective. A 1/3 resolve on their own

Question 6

What are clinical differences between preseptal and postseptal cellulitis in the orbit?

Answer 6

In Post-septal, there’s reduced visual acuity, reduced/painful eye movement, exophthalmos.

Orbital veins drain into the cavernous sinus giving potential route for an intracranial infection

Question 7

What is the name of the condition of excessive tearing in the eye?

Answer 7

Epiphora

Question 8

Name some differences between conjunctivitis and a subconjunctival haemorrhage?

Answer 8

Conjunctivitis is contagious dilitation of vessels that is uncomfortable with a watery discharge

The haemorrhage is a painless and spontaneous with no associated symptoms

Question 9

What are the 3 layers of the eye ball from outside to inside?

Answer 9

Sclera, Choroid and retina

Question 10

How is aqueous humour drained?

Answer 10

Drains through iridocorneal angle between iris and cornea and into canal of Schlemm

Question 11

What is the cause of a Glaucoma

Answer 11

An increase in intraocular pressure due to poor drainage of aqueous humour that can cause optic nerve damage

Question 12

What the medical term for double vision?

Answer 12

Diplopia

Question 13

What muscles are primarily responsible for horizontal movement of the eye? ABduction and ADduction

Answer 13

Lateral Rectus- Abducts
Medial Rectus- ADducts

Question 14

When the eye is positioned laterally, what muscle pair and powerful depressors and elevators?

Answer 14

The Superior and Inferior Obliques

Question 15

In the 2 acquired causes of a CN III lesion, what scenario is pupil reflex spared?

Answer 15

A vasculopathic, it is spared. In compressive it isn’t

Question 16

How can you determine if a cause of decreased visual acuity is due to a refractive or non refractive error?

Answer 16

In a refractive error, acuity will improve if light is seen through a pin hole because this late will not need to be refracted