Glaucoma (Acute Angle‑Closure)

Overview

Acute angle‑closure glaucoma (AACG) is a rapid, sight‑threatening form of glaucoma that occurs when the drainage angle between the iris and the cornea closes suddenly. This blockage prevents aqueous humor from exiting the eye, causing a sudden rise in intra‑ocular pressure (IOP). If untreated within hours, permanent optic nerve damage and irreversible vision loss can occur. AACG is considered an ophthalmic emergency.

Sources: Mayo Clinic, CDC, NIH.

Symptoms Checklist

• Severe, sudden eye pain (often described as a “stabbing” or “burning” sensation)
• Headache, usually on the same side as the affected eye
• Blurred or hazy vision
• Seeing halos or rainbow‑colored circles around lights
• Redness of the eye (conjunctival injection)
• Nausea and/or vomiting (due to the pain and elevated IOP)
• Pupillary dilation that does not react to light (mid‑dilated, non‑reactive pupil)

Risk Factors

• Age: Most common after age 60.
• Anatomy: Shallow anterior chamber or narrow drainage angle (more common in Asian ancestry).
• Hyperopia (farsightedness): Shorter eyeball length predisposes to angle closure.
• Family history: First‑degree relatives with angle‑closure glaucoma.
• Medications: Anticholinergics, antihistamines, phenothiazines, or any drugs that dilate the pupil.
• Other eye conditions: Cataract, uveitis, or ocular trauma that can push the iris forward.
• Systemic factors: Diabetes, hypertension, and sleep apnea have been linked to higher risk.

Diagnosis

Prompt evaluation by an eye‑care professional is essential. Typical diagnostic steps include:

1. Clinical history & symptom review – rapid onset of pain, halos, etc.
2. Slit‑lamp examination – assesses corneal edema, pupil size, and anterior chamber depth.
3. Gonioscopy – uses a special lens to directly view the angle and confirm it is closed.
4. Tonometry – measures intra‑ocular pressure; values often exceed 30‑40 mm Hg in AACG.
5. Fundus examination – evaluates optic nerve head for early signs of damage.
6. Ultrasound biomicroscopy (UBM) or Anterior segment OCT – imaging modalities that can quantify angle width.

Sources: Cleveland Clinic, Johns Hopkins Medicine.

Treatment Options

Because AACG is an emergency, treatment aims to lower IOP quickly, relieve pain, and reopen the angle.

Medical (Pharmacologic) Management

• Topical beta‑blockers (e.g., timolol) – decrease aqueous production.
• Alpha‑agonists (e.g., apraclonidine) – reduce production and increase outflow.
• Carbonic anhydrase inhibitors (e.g., dorzolamide, oral acetazolamide) – lower IOP by reducing fluid formation.
• Prostaglandin analogs (e.g., latanoprost) – increase uveoscleral outflow (used after acute phase).
• Miotic agents (e.g., pilocarpine 2%‑4%) – constrict the pupil to pull the iris away from the trabecular meshwork.
• Systemic hyperosmotic agents (e.g., oral glycerol, IV mannitol) – draw fluid out of the eye for rapid pressure reduction.

Surgical / Laser Interventions

• Laser peripheral iridotomy (LPI) – creates a tiny hole in the peripheral iris to provide an alternate pathway for aqueous flow; the definitive treatment for most cases.
• Laser iridoplasty – uses laser burns to contract the peripheral iris, widening the angle when LPI is insufficient.
• Trabeculectomy or tube shunt surgery – reserved for refractory cases where IOP remains uncontrolled.

Home / Supportive Care

• Follow the prescribed eye‑drop schedule precisely.
• Avoid over‑the‑counter decongestants or antihistamines that dilate pupils.
• Stay hydrated and limit caffeine, which can transiently raise IOP.
• Use protective eyewear to prevent trauma.

Prevention

• Regular eye exams: Adults over 40 (or earlier if high‑risk) should have a comprehensive dilated exam with gonioscopy.
• Prophylactic laser iridotomy: Recommended for eyes with a narrow angle but no symptoms, especially in high‑risk ethnic groups.
• Medication review: Discuss any new systemic or ocular drugs with your ophthalmologist.
• Control systemic diseases: Good management of diabetes and hypertension reduces overall ocular risk.
• Protective measures: Avoid prolonged darkness or bright light that forces pupil dilation; wear sunglasses outdoors.

Living With Glaucoma (Acute Angle‑Closure)

Even after successful treatment, lifelong monitoring is essential.

• Follow‑up schedule: Typically every 3–6 months initially, then annually if stable.
• Medication adherence: Missing drops can cause pressure spikes.
• Self‑monitoring: Be aware of any return of symptoms (pain, halos, vision changes) and report immediately.
• Vision aids: Low‑vision devices or contrast‑enhancing glasses may help if peripheral vision is affected.
• Lifestyle: Maintain a healthy weight, exercise regularly, and limit alcohol, which can affect IOP.
• Support networks: Glaucoma foundations and patient groups provide education and emotional support.

When to Seek Emergency Care

If you experience any of the following, go to the nearest emergency department or call emergency services (e.g., 911) immediately:

• Sudden, severe eye pain with or without headache.
<
• Rapid vision loss, blurred vision, or seeing halos around lights.
• Red eye accompanied by nausea or vomiting.
• Pupil that is markedly dilated and does not react to light.
• Any recurrence of symptoms after previous acute‑angle closure treatment.