Glaucomatous Type Cupping Caused by Internal Carotid Artery Compression: a Case Report

Area of Science:

• Ophthalmology
• Neurology
• Neuroimaging

Background:

• Normal tension glaucoma (NTG) is a progressive optic neuropathy characterized by visual field loss with intraocular pressure within the normal range.
• Compressive optic neuropathies can arise from various lesions, including tumors, aneurysms, and anatomical variations.
• Differentiating between NTG and compressive optic neuropathy is crucial for appropriate management and preventing irreversible vision loss.

Observation:

• A 71-year-old woman with diagnosed NTG presented with progressive right eye visual loss.
• Initial brain magnetic resonance imaging (MRI) was interpreted as normal.
• Re-evaluation of the MRI revealed compression of the right optic nerve by the right internal carotid artery.

Findings:

• The patient's symptoms and examination findings were initially suggestive of NTG but ultimately consistent with compressive optic neuropathy.
• Anatomical variation of a normal intracranial structure, the internal carotid artery, was identified as the cause of optic nerve compression.
• This case underscores the challenges in the differential diagnosis between NTG and compressive optic neuropathy.

Implications:

• This case highlights the critical importance of thorough clinical evaluation and reassessment of neuroimaging in cases of suspected optic neuropathy.
• It serves as a reminder that anatomical variations of common vascular structures can present as compressive optic neuropathy, mimicking other optic nerve diseases.
• Accurate diagnosis is essential to guide appropriate treatment strategies and improve patient outcomes in optic nerve disorders.