Acute Angle Closure Glaucoma

Question 1

What is Acute Angle-Closure Glaucoma (AACG)?

Answer 1

A condition where the iridocorneal angle is closed, preventing the trabecular meshwork from effectively draining aqueous humor, leading to a build-up of intraocular pressure. It is usually unilateral.

Question 2

What are the anatomical causes of AACG?

Answer 2

• Female (F:M ratio 3:1)
• Ethnicity (e.g., Chinese, Vietnamese, Inuit)
• Family history
• Short axial length (hypermetropia)
• Increasing age (lens thickness increases, anterior chamber depth decreases)

Question 3

What drugs can induce AACG?

Answer 3

• Adrenergic agents (e.g., phenylephrine)
• Anticholinergic agents (e.g., tricyclic antidepressants, tropicamide)
• Drugs that may cause ciliary body oedema (e.g., topiramate, sulphonamides)

Question 4

How can surgery cause AACG?

Answer 4

AACG can be induced by surgeries involving intraocular gas in aphakic eyes.

Question 5

What are the key signs of AACG?

Answer 5

• Reduced visual acuity
• Brick red eye
• Corneal oedema
• Vertically mid-dilated fixed pupil
• High intraocular pressure (IOP)
• Closed iridocorneal angle

Question 6

What are the common symptoms of AACG?

Answer 6

• Nausea
• Headaches
• Misty vision
• Halos around lights
• Light sensitivity

Question 7

What is the first step in managing AACG?

Answer 7

Emergency (same day) referral to an ophthalmologist with A2 first aid measures.

Question 8

What eye drop is used in the initial management of AACG?

Answer 8

Pilocarpine: 2% eye drops for blue eyes and 4% eye drops for brown eyes (usually ineffective if IOP > 40mmHg).

Question 9

What oral medication is used to treat AACG if the patient is not vomiting?

Answer 9

A stat dose of oral acetazolamide (Diamox) 500mg.

Question 10

What intravenous medication is given for AACG?

Answer 10

Intravenous acetazolamide or glycerol.

Question 11

What topical medications are used to manage high IOP in AACG?

Answer 11

Topical antihypertensive eye drops.

Question 12

What surgical options are available for treating AACG?

Answer 12

• Peripheral iridoplasty
• Peripheral iridotomy
• Cataract extraction

Question 13

What is the prognosis for AACG if treated quickly?

Answer 13

The prognosis is good if treatment is started quickly.

Question 14

What can happen if AACG is not treated promptly or if the condition is severe?

Answer 14

Irreversible damage to the optic nerve and blood vessels, leading to permanent vision loss.

Question 15

What is the role of pilocarpine in AACG management?

Answer 15

It is used to constrict the pupil and open the iridocorneal angle, though it is often ineffective if IOP exceeds 40mmHg.

Question 16

How does acetazolamide help in managing AACG?

Answer 16

It reduces aqueous humor production, lowering intraocular pressure.

Question 17

What are halos around lights a symptom of in AACG?

Answer 17

High intraocular pressure causing corneal oedema, which leads to seeing halos around lights.

Question 18

Why might a patient with AACG experience misty vision?

Answer 18

Corneal oedema from high intraocular pressure can cause misty or blurred vision.

Question 19

Why is AACG considered an ocular emergency?

Answer 19

If untreated, it can cause permanent vision loss due to optic nerve and vascular damage.

Question 20

What is the significance of the closed iridocorneal angle in AACG?

Answer 20

It prevents aqueous humor drainage, leading to a rapid increase in intraocular pressure.