Glaucoma, Acute Angle-Closure

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

• Results from closure of a preexisting narrow anterior chamber angle

• Predisposing factors

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

  • Enlargement of the crystalline lens with age

  • Inheritance, such as among Inuits and Asians

• Closure of the angle is precipitated by pupillary dilation and can occur

  • From sitting in a darkened theater

  • During times of stress

  • Following non-ocular administration of anticholinergic or sympathomimetic agents, for example

    • Nebulized bronchodilators

    • Atropine for preoperative medication

    • Antidepressants

    • Bowel or bladder antispasmodics

    • Nasal decongestants

    • Tocolytics

  • From pharmacologic mydriasis (rarely)

Secondary acute angle-closure glaucoma

• Does not require a preexisting narrow angle

• May occur in anterior uveitis, with dislocation of the lens, with hemodialysis, or due to various drugs

• Symptoms are the same as in primary acute angle-closure glaucoma, but differentiation is important because of different management

Symptoms and Signs

• Patients usually seek treatment immediately because of extreme pain and blurred vision, though there are subacute cases

• May present as recurrent headache in subacute cases

• Typically, the blurred vision is associated with halos around lights

• Nausea and abdominal pain may occur

• The eye is red, the cornea cloudy, and the pupil moderately dilated and nonreactive to light

Differential Diagnosis

• Conjunctivitis

• Acute uveitis

• Corneal disorders

• Intraocular pressure is usually over 50 mm Hg, producing a hard eye on palpation

• Reduction of intraocular pressure is initial treatment, regardless of mechanism

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

• Osmotic diuretics, such as oral glycerin and intravenous urea or mannitol

  • May be necessary if there is no response to acetazolamide

  • Dosage of all three: 1–2 g/kg

• Definitive treatment depends on the mechanism

Primary acute angle-closure glaucoma

• Topical 4% pilocarpine

  • Used when intraocular pressure starts to fall to reverse underlying angle closure

  • Dosage: 1 drop every 15 minutes for 1 hour and then four times a day

• Laser peripheral iridotomy or surgical peripheral iridectomy

  • Definitive treatment

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

  • Whether prophylactic laser peripheral iridotomy should be undertaken in asymptomatic patients with narrow anterior chamber angles is mainly influenced by the risk of the more common chronic angle closure

• Cataract extraction is a possible alternative

Secondary acute angle-closure glaucoma

• Additional treatment is determined by the cause

Prognosis

• If left untreated, severe and permanent visual loss occurs within 2–5 days after onset of symptoms

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

When to Refer

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