H40.23 Intermittent angle-closure glaucoma

Name of the Condition

• Intermittent Angle-Closure Glaucoma

Summary

Intermittent angle-closure glaucoma is a form of glaucoma marked 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.

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 optical coherence tomography (OCT) to evaluate optic nerve health. Visual field tests may detect peripheral vision loss, and a history of intermittent symptoms is critical for identification.

Treatment Options

• Laser iridotomy to create a drainage channel.
• Medications to lower intraocular pressure (e.g., beta-blockers, prostaglandin analogs).
• Pupil-constricting drops to prevent angle closure.
• Surgical interventions (e.g., lens extraction) in select cases.

Prognosis and Follow-Up

With appropriate management, vision loss can be minimized, but regular monitoring is essential to detect progression. Follow-up typically includes periodic intraocular pressure checks, optic nerve evaluations, and visual field testing. Untreated or poorly controlled cases may lead to permanent vision impairment.

Complications

• Permanent vision loss from optic nerve damage.
• Chronic elevated intraocular pressure.
• Acute angle-closure episodes with severe symptoms.
• Glaucomatous optic neuropathy.

Lifestyle & Prevention

• Avoid medications that dilate pupils without consulting a provider.
• Use adequate lighting to reduce pupil dilation in low-light environments.
• Manage underlying risk factors (e.g., hyperopia correction).
• Attend regular eye exams, especially if risk factors exist.

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 episode. Routine follow-up is necessary for ongoing monitoring, even if symptoms are mild or intermittent.

Tips for Medical Coders

Document the intermittent nature of the angle closure, including triggers (e.g., pupil dilation) or resolution patterns, to support code assignment. Note any acute episodes or treatment responses, as these may impact clinical coding and billing. Ensure documentation aligns with the ICD-10-CM guidelines for H40.23.