A rare presentation of saccular aneurysm at junction of middle carotid artery and internal carotid artery mimicking the normal tension glaucoma

Abstract

Acquired (pathologic) excavation of the optic cup is not always due to glaucoma. Ophthalmological signs of pathological disc cupping have been recognised in patients with normal intraocular pressures and with optic atrophy of various causes including ischaemic and compressive optic neuropathy, optic neuritis and trauma. Intracranial lesions have been reported to mimic the clinical presentation of glaucomatous optic disc changes and have also resulted in misdiagnosis. Optic atrophy caused by intracranial lesions shows pallor more than cupping. The macular nasal–temporal ratio compares the nasal and temporal thickness of the macular ganglion cell and inner plexiform layer and can be used to differentiate between compressive and non-compressive lesions as depicted in this case. This case report also suggests the importance of different imaging modalities in diagnosing compressive lesions and differentiating them from similar conditions.