Open Angle Glaucoma Flashcards
1
Q
What is a glaucoma?
A
Optic nerve damage that is caused by a significant rise in IOP which is caused by a blockage in the aqueous humour
2
Q
What are the 2 types of glaucoma?
A
Open Angle and Closed Angle
3
Q
What is the pathophysiology of open-angle glaucoma?
A
- Gradual increase in resistance through the trabecular meshwork making it more difficult for aqueous humour to flow through the meshwork and exit the eye and so the pressure builds gradually -> chronic
4
Q
What is the difference between open angle and closed angle glaucoma?
A
- In open, the angle between the iris and the cornea is normal whereas in closed, it is atleast partially reduced
5
Q
What is cupping of the optic disc?
A
- In the optic disc, there is a normal small indent known as the optic cup
- When pressure in the eye increases, the indent becomes larger and deeper (greater than 0.5 of the size of the optic disc is abnormal)
6
Q
What are the risk factors for open angle glaucoma?
A
- Increasing age
- Family history
- Black ethnic origin
- Near-sightedness (myopia)
7
Q
How does open-angle glaucoma present?
A
- Often asymptomatic for a long time
- Diagnosed at optometry usually
- If symptomatic, affects peripheral vision first eventually leading to tunnel vision
- Gradual onset of pain, headaches, blurred vision and halos around the eyes at night also present
8
Q
How do you measure intraocular pressure?
A
- Non-contact tonometry used commonly
- Goldmann applanation tonometry is the gold standard
9
Q
What are the investigations for OA glaucoma?
A
- GAT
- Fundoscopy
- Visual field assessment
10
Q
What is the management of open-angle glaucoma?
A
- Aim is to reduce intraocular pressure
- Selective laser trabeculoplasty should be offered to those with IOP > 24
- Second line: Prostaglandin analogue drops e.g. latanoprost which help with outflow
- Other options include topical carbonic anhydrase inhibitors e.g.. dorzolamide or topical beta blocker e.g. timolol
