H40.233 Intermittent angle-closure glaucoma, bilateral

Name of the Condition

• Intermittent Angle-Closure Glaucoma, Bilateral

Summary

Intermittent angle-closure glaucoma, bilateral, is a form of glaucoma characterized by periodic, temporary closure of the drainage angle in both eyes, leading to episodic increases in intraocular pressure. These episodes may resolve spontaneously or require intervention, and the condition carries a risk of progressive optic nerve damage over time if not managed. The term "intermittent" reflects the recurring nature of the angle closure, while "bilateral" specifies that both eyes are affected.

Causes

The condition stems from anatomical factors that predispose the drainage angles in both eyes to intermittent blockage, such as narrow angles or thickened lenses. Episodes may be triggered by factors like pupil dilation (e.g., in low light or with certain medications), which can temporarily worsen the angle closure. Underlying structural abnormalities in the anterior segments of both eyes may also contribute.

Risk Factors

• Anatomically narrow drainage angles in both eyes.
• Farsightedness (hyperopia).
• Age over 40.
• Family history of glaucoma.
• Asian or Inuit descent.
• Pupil-dilating medications or conditions.

Symptoms

• Episodic eye pain or discomfort in both eyes.
• Blurred vision during attacks.
• Halos around lights.
• Headaches.
• Nausea (in acute episodes).
• Gradual peripheral vision loss over time.

Diagnosis

Diagnosis requires a comprehensive eye exam, including tonometry to measure intraocular pressure, gonioscopy to assess the drainage angle, and visual field testing to detect optic nerve damage. Imaging or additional tests may be used to evaluate structural changes in the anterior segment. Bilateral involvement is confirmed by examining both eyes.

Treatment Options

Treatment aims to prevent acute attacks and manage chronic risk. Options include medications (e.g., topical or systemic agents to reduce intraocular pressure), laser iridotomy to create a drainage pathway, or surgical procedures (e.g., trabeculectomy) for refractory cases. Prophylactic treatment may be considered for the unaffected eye in unilateral cases, but bilateral management focuses on controlling both eyes.

Prognosis and Follow-Up

With proper management, prognosis is generally favorable, but untreated episodes can lead to permanent vision loss. Regular follow-up is essential to monitor intraocular pressure, optic nerve health, and treatment efficacy. Adjustments to therapy may be needed over time to address progression or new symptoms.

Complications

Potential complications include acute angle-closure glaucoma (a medical emergency), permanent optic nerve damage, and irreversible vision loss. Recurrent episodes may increase the risk of chronic glaucoma or require more aggressive intervention.

Lifestyle & Prevention

• Avoid triggers like low-light environments or medications that dilate pupils without consulting a provider.
• Manage underlying conditions (e.g., hyperopia) that may contribute to angle closure.
• Attend regular eye exams to detect early changes.

When to Seek Professional Help

Seek immediate care for sudden eye pain, blurred vision, halos around lights, or nausea, as these may indicate an acute attack. Routine follow-up is necessary for ongoing monitoring, even if symptoms are mild or intermittent.

Tips for Medical Coders

Use H40.233 for bilateral intermittent angle-closure glaucoma. Document laterality (bilateral) and specify if episodes are acute or chronic. Include details on triggers, treatment responses, or structural findings to support coding accuracy. Ensure documentation aligns with clinical findings and avoids ambiguity in laterality or episode frequency.