Ophthalmology

Question 1

What is glaucoma?

Answer 1

Optic nerve damage caused by a rise in intraocular pressure

Question 2

What causes raised intraocular pressure in glaucoma?

Answer 2

A blockage preventing aqueous humour trying to leave the eye

Question 3

What is normal intraocular pressure?

Answer 3

10-21 mmHg

Question 4

What produces aqueous humour?

Answer 4

the ciliary body

Question 5

Describe the pathway of aqueous humour from the ciliary body into general circulation:

Answer 5

Ciliary body -> around the lens, under the iris, through the anterior chamber, through the trabecular meshwork and into the canal of Schlemm -> general circulation

Question 6

Normal intraocular pressure is 10-20mmHg, what creates this pressure?

Answer 6

Flow of aqueous humour through the trabecular meshwork into the canal of Schlemm

Question 7

Describe the pathophysiology of open-angle glaucoma:

Answer 7

Resistance through the trabecular meshwork gradually increases.
This makes it more difficult for the aqueous humour to flow through the meshwork and exit the eye.

Question 8

Describe the pathophysiology of acute angle-closure glaucoma:

Answer 8

The iris bulges forward and seals off the trabecular meshwork from the anterior chamber preventing aqueous humour from draining. This leads to a continual build up of pressure = emergency

Question 9

What is optic cupping?

Answer 9

At the centre of the optic disc is the optic cup, a small indent. Increased pressure in the eye causes the cup to widen and deepen. An optic cup greater than 0.5 the size of the optic disc is abnormal.

Question 10

Give 4 risk factors of glaucoma:

Answer 10

1. increasing age
2. family history
3. black ethnic origin
4. nearsightedness (myopia)

Question 11

How does glaucoma present?

Answer 11

Usually asymptomatic and discovered on routine screening.

Affects peripheral vision first - gradually causing tunnel vision.

Question 12

What makes up the fibrous layer of the eyeball?

Answer 12

Sclera - visible white part of the eye, provides attachment for the extraocular muscles
Cornea - transparent layer positioned at the front of the eye

Question 13

What makes up the vascular layer of the eyeball? (3)

Answer 13

Choroid, ciliary body, iris

Question 14

What makes up the inner layer of the eyeball?

Answer 14

the retina - made up of two parts: outer pigmented layer, inner neural layer

Question 15

What artery supplies the eyeball?

Answer 15

Primarily the ophthalmic artery which is a branch of the internal carotid arising immediately distal to the cavernous sinus

Question 16

What does the cavernous sinuses contain?

Answer 16

Oh, COAT:
Occulomotor nerve
internal Carotid artery
Ophthlamic nerve
Abducens nerve
Trochlear nerve