Acute Angle-Closure Glaucoma
Acute angle-closure glaucoma (AACG) is a sudden and dangerous rise in eye pressure caused by a blockage in the eye’s internal drainage system. It is a medical emergency that can lead to permanent vision loss within hours if not treated promptly.
Inside the eye, a clear fluid called aqueous humour is constantly produced and normally drains away through tiny channels. In an acute attack, these channels are suddenly blocked, causing pressure to spike—often when the pupil enlarges in dim lighting.
Typical Symptoms
Symptoms of an acute attack appear suddenly and intensely. They cannot be ignored:
Severe Pain and Headaches
Intense eye pain often accompanied by a severe headache, nausea, and vomiting. The eye will typically appear very red.
Visual Rainbows and Blur
Seeing rainbow-coloured halos around lights and experiencing blurred, hazy, or rapidly worsening vision.
Medical Emergency: Irreversible damage to the optic nerve can occur within hours. If you experience these symptoms, seek immediate emergency eye care.
Causes and Risk Factors
The blockage occurs when the iris (coloured part of the eye) sits too close to the drainage angle. Risk factors include:
- - Eye Shape: Farsightedness (hyperopia), shallow anterior chambers, or shorter eye length.
- - Age & Gender: Risk increases over 40 (peaking between 60–70); females are affected more often.
- - Ethnicity: Significantly higher incidence in Asian and Alaska Native populations.
- - Genetics: A family history of angle-closure glaucoma.
Incidence and Prevalence
| Population Group | Estimated Incidence |
|---|---|
| White Populations | ~1 in 1,000 individuals |
| Asian Populations | ~1 in 100 individuals |
| Alaska Native Populations | ~2 to 4 in 100 individuals |
Treatment and Management
Immediate Medical Treatment
The first goal is to lower eye pressure quickly using a combination of medications:
- - Acetazolamide: To rapidly reduce fluid production.
- - Topical Drops: Beta-blockers, steroids, and pilocarpine to open the drainage angle.
- - Pain Management: Medication for intense pain and nausea.
Definitive Procedures
Once pressure is controlled, procedures are performed to prevent recurrence:
- - Laser Peripheral Iridotomy: A laser creates a tiny opening in the iris to allow fluid to bypass the blockage.
- - Preventative Care: The "quiet" eye is often treated preventatively to avoid a future attack.
Clinical References
1. Glaucoma Research Foundation.
Acute Angle-Closure Glaucoma. Available at:
https://www.glaucoma.org
2. American Academy of Ophthalmology.
Angle-Closure Glaucoma: Mechanism and Risks.
3. eMedicine Health. Glaucoma Emergencies and Management.
4. Healthline. Pterygium: Causes, Symptoms & Diagnosis.