What are the symptoms and treatment options for narrow angle glaucoma?

Symptoms of Narrow Angle Glaucoma

The primary symptoms of narrow angle glaucoma include eye pain, blurred vision, halos around lights, headache, nausea/vomiting, eye redness, and a mid-dilated pupil, particularly during an acute angle-closure crisis (AACC). 1

Clinical Presentation

Acute Angle-Closure Crisis (AACC)

AACC presents with sudden onset of symptoms including:

• Pressure-induced corneal edema causing blurred vision
• Multicolored halos around lights
• Mid-dilated, often nonreactive pupil
• Conjunctival and episcleral vascular congestion (eye redness)
• Severe eye pain
• Headache
• Nausea and/or vomiting 1

These symptoms result from a rapid rise in intraocular pressure (IOP) when the anterior chamber angle becomes suddenly obstructed. This is considered a true ophthalmologic emergency requiring immediate treatment to prevent permanent vision loss or blindness. 2

Chronic Forms

Patients with chronic forms of primary angle-closure disease (PACD) may be asymptomatic or experience intermittent symptoms such as:

• Transient blurred vision
• Mild eye discomfort
• Headaches
• Brief episodes of halos around lights 1

Atypical Presentations

It's important to note that some patients may present with atypical symptoms:

• Some patients may experience acute visual impairment without pain 3
• Symptoms can be precipitated by certain activities like bending over 3
• Symptoms may occur after pupillary dilation during eye examinations 2

Risk Factors for Narrow Angle Glaucoma

Understanding risk factors helps identify patients who should be monitored closely:

• Asian descent
• Hyperopia (farsightedness)
• Older age (typically >50 years)
• Female gender
• Short axial length
• Thick and anteriorly positioned crystalline lens
• Steep corneal curvature
• Family history of angle closure 1, 2

Diagnostic Classification

Modern classification of primary angle-closure disease includes:

1. Primary angle-closure suspect (PACS): ≥180 degrees iridotrabecular contact (ITC), normal IOP, no optic nerve damage
2. Primary angle closure (PAC): ≥180 degrees ITC with peripheral anterior synechiae (PAS) or elevated IOP, no optic neuropathy
3. Primary angle-closure glaucoma (PACG): ≥180 degrees ITC with PAS, elevated IOP, and optic neuropathy
4. Acute angle-closure crisis (AACC): Occluded angle with symptomatic high IOP
5. Plateau iris configuration/syndrome: Narrow angle due to anteriorly positioned ciliary body with deep central anterior chamber 1

Treatment Approaches

For Acute Angle-Closure Crisis

Immediate treatment is essential to prevent permanent vision loss:

1. Medical therapy to rapidly lower IOP:

   • Systemic carbonic anhydrase inhibitors (e.g., acetazolamide) 4, 5
   • Topical beta-blockers, alpha-2 agonists, and prostaglandin analogs
   • Osmotic agents (e.g., mannitol) if necessary 2, 5
   • Parasympathomimetics (e.g., pilocarpine) 5

2. Definitive treatment:

   • Laser peripheral iridotomy (LPI) or surgical iridectomy once IOP is controlled
   • Prophylactic LPI in the fellow eye 1, 2

3. For refractory cases:

   • Lens extraction (particularly effective for some PAC and PACG patients) 1
   • Trabeculectomy or glaucoma drainage devices 2

For Chronic Forms

Management focuses on prevention of progression:

• Laser peripheral iridotomy
• IOP-lowering medications
• Lens extraction in appropriate cases 1

Medication-Induced Angle Closure

Several medications can precipitate angle closure in susceptible individuals:

• Adrenergic agents
• Anticholinergic medications
• Tricyclic and tetracyclic antidepressants
• Sulfa-based drugs
• SSRIs and SNRIs 2, 6

Monitoring and Follow-up

After an episode of AACC, careful monitoring is essential:

• Watch for transient optic disc swelling after laser iridotomy 7
• Regular IOP monitoring
• Gonioscopy to verify improvement in angle configuration
• Assessment for glaucomatous optic neuropathy 1

Prognosis

Without treatment, the prognosis for AACC is poor:

• 18% of eyes may become blind (10% from glaucoma)
• 48% may develop glaucomatous optic neuropathy
• 58% may have visual acuity worse than 20/40 within 4-10 years following an AACC 1

Early recognition of symptoms and prompt treatment are crucial to prevent these outcomes and preserve vision.