Angle Closure Glaucoma

Question 1

What is glaucoma?

Answer 1

Glaucoma is a group of eye conditions that damage the optic nerve which is responsible of transmitting visual information from the eye to the brain.

Question 2

What is angle closure glaucoma?

Answer 2

The term angle closure refers to occlusion of trabecular meshwork by the peripheral iris, obstructing aqueous outflow thereby increasing IOP.

Question 3

Normal intraocular pressure?

Answer 3

10-21 mmHg

Question 4

Epidemiology of CAG?

Answer 4

• It accounts for a significant number of cases among persons of eastern and southern Asian descent( approximately 12 million).
• It is common in Asian people, less common in white people and least common in blacks
• Women to men ratio is 4:1
• Glaucoma is the second most common cause of blindness worldwide including Malawi.

Question 5

Describe secondary angle closure?

Answer 5

Secondary angle closure glaucoma is caused by the impairment of aqueous outflow secondary to apposition between peripheral iris and trabeculum.

Question 6

Pathophysiology of CAG?

Answer 6

Blocked flow of aqueous humor pushes iris forward. When iris is pushed against trabecular meshwork, aqueous humor cannot flow out of eye(angle closure), increasing IOP
Two mechanisms
1. ‘’PUSHING’’ of iris from behind
‘2. ’PUSHING’’ of iris forward

Question 7

Signs of CAG?

Answer 7

1. Red eye
2. Reduced visual acuity
3. Corneal edema
4. High intraocular pressure
5. Closed iridocorneal angle on gonioscopy
6. Optic disc edema and hyperemia on ophthalmoscopy

Question 8

Symptoms of CAG?

Answer 8

1. Headache
2. Photophobia
3. Nausea and vomiting
4. Sudden onset of severe painful eye
5. Blurred vision
6. Halos around lights

Question 9

Ddx of CAG?

Answer 9

1. Inflammatory open angle glaucoma
2. Focal ischemic disc
3. Senile sclerotic disc
4. Aqueous misdirection
5. Acute glaucoma syndromes

Question 10

Investigations of CAG?

Answer 10

1. Tonometry
2. Pachymetry
3. Gonioscopy
4. Perimetry
5. Optical Coherence Tomography
6. Fundoscopy

Question 11

Management of CAG?

Answer 11

1. Acute angle-closure glaucoma is an ophthalmic emergency
2. Requires urgent treatment to prevent irreversible optic nerve damage

Question 12

Treatment goals for CAG?

Answer 12

1. Preserve visual function
2. Lower IOP
3. Neuroprotection

Question 13

Immediate management of CAG?

Answer 13

Acetazolamide 500mg IV stat (then 250mg PO QID).
β-blocker (e.g. timolol 0.5% stat, then Bd)
Sympathomimetic (e.g. apraclonidine 1% stat).
Steroid (e.g. prednisolone 1% stat, then q 30–60min).
When IOP begins to drop administer pilocarpine 2% QID

Question 14

Intermediate treatment of CAG?

Answer 14

If IOP still not improvin use
1. Guttae (drops) of glycerin
2. or Mannitol to temporarily reduce corneal oedema)

Question 15

Definitive management of CAG?

Answer 15

1. Laser iridoplasty
2. Argon laser trabeculoplasty

Question 16

Complications of CAG?

Answer 16

1. Cataract
2. Absolute glaucoma
3. Atrophy of the retina and optic nerve