Table 2.
Differential diagnosis amongst NA-AION, A-AION, optic neuritis, anterior orbital lesions.
| Clinical Features | NA-AION | A-AION | Papillitis | Orbital Lesions |
|---|---|---|---|---|
| Patient’s age | any, most frequent over 50 years | over 50 years, most frequent over 70 years | any, most common in young | any |
| Gender predilection | male | female | female | any |
| Visual loss onset | acute | acute, poor VA * | semi-acute | gradually slowly progressive |
| Onset laterality | unilateral | unilateral or bilateral (30% of cases) | unilateral | unilateral |
| Visual field defect pattern | altitudinal or arcuate | altitudinal or arcuate | central, centro-cecal, arcuate | arcuate, peripheral |
| OD edema | any type, segmental, evolution to OD atrophy | chalky white, segmental, evolution to OD cupping | mild, hyperemic, evolution to OD atrophy | pale, lasting over 4–6 weeks, evolution to OD atrophy |
| OD the fellow eye at onset | small C/D | normal or large C/D | normal or large C/D | normal or large C/D |
| Peripapillary hemorrhages | common | common | uncommon | uncommon |
| Relative afferent pupillary defect | present | present | present | present |
| Ocular pain | uncommon (10–15% of cases) | common (75% of cases) | common (95% of cases), worse with eye movements | common |
| Premonitory symptoms | uncommon | amaurosis fugax and/or diplopia (30% of cases) | uncommon | uncommon |
| Associated ocular finding | OD drusen, hypertensive or diabetic retinopathy | cotton wool spots, central retinal o cilioretinal artery occlusion | possible intraocular inflammation, retinal vasculitis | ptosis, proptosis, lid and eye movements abnormalities |
| Presence of vasculopatic risk factors | common | common | uncommon | uncommon |
| Associated systemic symptoms | absent | fever, malaise, jaw claudication, headache, abnormal temporal artery ** | paresthesia, diplopia, ataxia, weakness, systemic disease | signs of systemic malignancy may be present |
| Disease course | frequent spontaneous visual recovery | rare spontaneous visual recovery, severe prognosis | frequent spontaneous visual recovery | progressively worse |
| FAG features of OD ischemia | common | common and severe | absent | absent |
| serous ESE and CRP levels | normal | significantly high | normal | normal |
| MRI brain and orbit findings | none | ON sheath and orbital fat enhancement | ON enhancement; frequent signs of demyelination | presence of orbital compressive lesions |
| Response to CS therapy | unclear | present, stop of further vision loss and systemic complications | present, with good visual prognosis | absent |
NA-AION = non-arteritic anterior ischemic optic neuropathy; A-AION = arteritic anterior ischemic optic neuropathy; OD = optic disk; C/D = cup-to-disk ratio; ON = optic nerve; CS = corticosteroids; CRP = C-reactive protein; * = VA at onset ≤ counter finger in >50% of cases; ** = 25% of A-AION are “occult”, i.e., without systemic symptoms.