Non-Glaucomatous Optic Neuropathies

Primary Causes

Giant cell arteritis is the most common non-embolic vascular cause in patients over 50 and represents an ophthalmologic emergency, according to the American College of Rheumatology 1
GCA causes inflammatory disease of the proximal ocular artery with vessel wall thickening and occlusion, resulting in simultaneous ischemia of the optic disc, as stated by the American Academy of Ophthalmology 1
Immediate high-dose systemic corticosteroid therapy is critical to prevent vision loss in the fellow eye, as recommended by the American College of Rheumatology 1

Pallor of the neuroretinal rim is not the hallmark feature distinguishing non-glaucomatous from glaucomatous cupping, but in glaucoma, the neuroretinal rim maintains its color despite thinning, according to the American Academy of Ophthalmology 3, 4
Glaucomatous cupping typically shows preferential inferior and superior pole damage (violating the ISNT rule), as stated by the American Academy of Ophthalmology 3, 4
Absence of disc hemorrhages (which are characteristic of glaucoma) and absence of beta-zone parapapillary atrophy (characteristic of glaucoma) can suggest non-glaucomatous cupping, according to the American Academy of Ophthalmology 3, 4

Age over 50 with acute vision loss suggests AAION requiring emergent evaluation, as stated by the American College of Emergency Physicians 1
Temporal headache, jaw claudication, or polymyalgia rheumatica symptoms suggest giant cell arteritis, according to the American College of Rheumatology 1
Intraocular pressure measurement and gonioscopy to assess anterior chamber angle are essential in the diagnostic approach, as recommended by the American Academy of Ophthalmology 5
Magnified stereoscopic visualization through dilated pupil using slit-lamp biomicroscope and red-free illumination to evaluate retinal nerve fiber layer are crucial for diagnosis, according to the American Academy of Ophthalmology 1

Low ocular perfusion pressure contributes to inadequate blood flow to the optic nerve head, increasing the risk of non-arteritic anterior ischemic optic neuropathy (NAION), as stated by the American Heart Association 2
Previous NAION in one eye increases risk for the fellow eye, according to the American Academy of Ophthalmology 2
Risk factors for NAION overlap significantly with those for glaucoma, but management approaches differ, as stated by the American Academy of Ophthalmology 2