Glaucoma

Question 1

What is glaucoma?

Answer 1

Blanket term for a variety of conditions with different features and mechanism
- all have optic nerve damage which leads to visual field loss and can lead to eventual blindness

Question 2

What are the risk factors for glaucoma?

Answer 2

High IOP (>21mmHg)
Family history of glaucoma
Race
Systemic hypertension 
CVD
Migraine
Previous ocular disease

Question 3

Whats the most likely cause of primary glaucoma?

Answer 3

Congenital

Question 4

What is the most likely cause of secondary glaucoma?

Answer 4

From other ocular disease, trauma

Question 5

Where is aqueous humour produced?

Answer 5

In the outermost layer of cells in the ciliary process

Question 6

What happens when the trabecular meshwork gets damaged?

Answer 6

It prevents drainage of the aqueous humour, this leads to build up which increases IOP

Question 7

What is the aim of anti-glaucoma drug treatment?

Answer 7

Reduce IOP
Drug should have sufficient duration of action

This should provide:

• Preservation of visual field
• compatibility with other treatments
• No topical/systemic side effects

Question 8

Which drugs class of drugs are first line treatment for glaucoma?

Answer 8

Prostaglandins and prostamide analogues

Question 9

Describe how prostaglandin analogues work

Answer 9

Help with aqueous humour outflow
They have a unique mechanism to decrease IOP
E2 is unstable as an analogue so PGF2⍺ is used. Fp receptors are present on colliery body and muscle sclera.

Lower IOP by up to 35%

They have a long duration of action, use once a night.

Question 10

Give examples of prostaglandin analogues used in glaucoma

Answer 10

Latanaprost
Tafluprost
Travoprost

Question 11

Describe how prostamide analogues work

Answer 11

They increase uveoscleral and trabecular outflow. Resistance to outflow is reduced by remodelling extracellular matrix which is achieved by:

• Increase matrix metalloproteinases
• degrade collagen and exreacellular matriculates
• decrease resistance of ciliary muscle and sclera to increase outflow

Question 12

What are the side effects associated with prostaglandin and prostamide analogues?

Answer 12

Red eye
Increased pigmentation in rise, eyelash and periocular skin 
Eyelash growth
Preciptate/worsen cystoid macular oedema
Sensitivity to light 
Contraindicated in pregnancy