Glaucoma, Acute Angle-Closure

Key Features

Essentials of Diagnosis

• Older age group, particularly farsighted individuals

• Rapid onset of severe pain and profound visual loss with "halos around lights"

• Red eye, cloudy cornea, dilated pupil

• Hard eye on palpation

General Considerations

• Primary acute angle-closure glaucoma

  • Occurs in eyes with narrow anterior chamber angles, for which precipitating factors are

    • Shallow anterior chamber, which may be associated with farsightedness or a small eye (short axial length)

    • Age (owing to enlargement of the crystalline lens)

    • Inheritance, being particularly prevalent among Inuits and Asians

  • May be precipitated by

    • Pupillary dilation from sitting in the dark

    • Stress

    • Medications with anticholinergic or sympathomimetic activity

    • Pharmacologic mydriasis for ophthalmologic examination (rarely)

  • Subacute primary angle-closure glaucoma may present as recurrent headache

• Secondary acute angle-closure glaucoma

  • Does not require a preexisting narrow angle

    • May occur in uveitis, with hemodialysis, or with medications with anticholinergic or sympathomimetic activity (rare)

  • Important to differentiate from primary acute angle-closure glaucoma because of differences in management

Clinical Findings

• Extreme ocular pain

• Blurred vision, typically with halos around lights

• Nausea and vomiting

• The eye is red and the cornea is cloudy, usually with a moderately dilated, nonreactive pupil

• Intraocular pressure usually > 50 mm Hg, producing hard eye on palpation

Diagnosis

• Markedly elevated intraocular pressure with shallow anterior chamber in both eyes

• Must be differentiated from conjunctivitis, acute uveitis, and corneal disorders

Treatment

• Immediate evaluation and treatment by an ophthalmologist are essential

• A single 500-mg intravenous dose of acetazolamide, followed by 250 mg orally four times a day, together with topical medications is usually sufficient to lower intraocular pressure

• If no response to acetazolamide, consider 1–2 g/kg of an osmotic diuretic, such as oral glycerin, intravenous mannitol, or intravenous urea

• After intraocular pressure is reduced, topical 4% pilocarpine, 1 drop every 15 min for 1 h then four times a day, is used to reverse the angle closure

• Definitive treatment is generally

  • Laser peripheral iridotomy

  • Surgical peripheral iridectomy

  • Cataract extraction, which is becoming first-line treatment for primary acute angle-closure glaucoma

• All patients with primary acute angle closure should undergo prophylactic laser peripheral iridotomy to the unaffected eye, unless that eye has already undergone cataract or glaucoma surgery

Outcome

Prognosis

• Untreated acute angle-closure glaucoma results in severe and permanent visual loss within 2–5 days after onset of symptoms

• Affected patients need to be monitored for development of chronic glaucoma

When to Refer

• Any patient with suspected acute angle-closure glaucoma must be referred emergently to an ophthalmologist

References