Acute Glaucoma (1*)

Question 1

What is Glaucoma?

What is the pathophysiology of Acute Glaucoma?

What are its risk factors?

Why is this an emergency?

Answer 1

➊ Optic nerve damage due to a rise in intra-ocular pressure, which is caused by a blockage in the drainage of aqueous humour

➋ Iris bulges forward and seals off the trabecular meshwork from the anterior chamber, therefore preventing the drainage of the aqueous humour = Quick increase in pressure
• Pressure then builds up in the posterior chamber, therefore worsening the angle closure

➌ • Age
• Female
• FHx
• Anti-muscarinics, Adrenergics, Anticholinergics, TCAs

➍ Can lead to permanent loss of vision

Question 2

How does it present?

When are the symptoms worse?
→ Why?
→ What should therefore be avoided when examining the eye in these cases?

What is seen O/E?

Answer 2

➊ • Severely painful red eye
• Blurred vision
• Halos around lights
• Headache, N+V

➋ At night
→ Pupil dilates and closes the angle further
→ Mydriatics (pupil dilator)

➌ Red eye, FIXED dilated pupil, Decreased visual acuity

Question 3

Management:
What can be done conservatively straight away?

What is the mainstay of treatment?
→ How does it work?

What other medications are given?

What is the definitive management option?

Answer 3

➊ Lie pt flat on their back (relieves pressure)

➋ Pilocarpine eye drops (2% if blue, 4% if brown)
→ • Muscarinic agonists → pupil constriction and ciliary muscle contraction
• Pulls iris away from trabecular network
• Both lead to more efficient aqueous drainage

➌ • Acetazolamide 500mg PO
‣ Carbonic Anhydrase Inhibitor → Less production of aqueous humour
• Timolol - B-blocker to decrease production of aqueous humour

➍ Iridotomy – Hole made into iris to allow aqueous humour to flow from posterior chamber into anterior chamber, therefore opening the angle and relieving pressure from the iris onto the cornea