H40.239 Intermittent angle-closure glaucoma, unspecified eye

Name of the Condition

• Intermittent Angle-Closure Glaucoma, Unspecified Eye

Summary

Intermittent angle-closure glaucoma, unspecified eye, is a form of glaucoma characterized by periodic, temporary closure of the eye's drainage angle, 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 "unspecified eye" indicates that laterality is not documented.

Causes

The condition stems from anatomical factors that predispose the drainage angle to intermittent blockage, such as a narrow angle or a thickened lens. 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 eye's anterior segment may also contribute.

Risk Factors

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

Symptoms

• Episodic eye pain or discomfort.
• 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. Episodes may be documented during acute attacks, and imaging or additional tests may be used to evaluate structural abnormalities.

Treatment Options

Treatment focuses on preventing acute attacks and managing intraocular pressure. Options include medications (e.g., topical or systemic agents to reduce pressure), laser therapy (e.g., iridotomy to create a drainage channel), or surgery (e.g., trabeculectomy) for refractory cases. Prophylactic measures, such as avoiding triggers like certain medications, may also be recommended.

Prognosis and Follow-Up

With appropriate management, the prognosis is generally favorable, but recurrent episodes can lead to permanent vision loss if optic nerve damage occurs. Regular follow-up appointments are essential to monitor intraocular pressure, optic nerve health, and treatment efficacy. Adjustments to therapy may be needed based on disease progression.

Complications

Potential complications include acute angle-closure glaucoma (a medical emergency), permanent vision loss due to optic nerve damage, and chronic elevated intraocular pressure. Untreated episodes may also increase the risk of corneal edema or cataracts.

Lifestyle & Prevention

Lifestyle modifications may help reduce the risk of attacks, such as avoiding low-light environments that cause pupil dilation, using caution with medications that dilate the pupil, and maintaining regular eye exams. Early detection of anatomical risk factors can enable preventive interventions like laser iridotomy.

When to Seek Professional Help

Seek immediate medical attention for sudden eye pain, severe headache, blurred vision, or halos around lights, 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

Document the eye laterality when known (right, left, or bilateral) for specificity. If laterality is not documented, use "unspecified eye" as indicated. Ensure clinical documentation supports the intermittent nature of the angle closure, including episode frequency, triggers, or treatment responses. Code H40.239 is appropriate when the eye is not specified.