In an 88-year-old man with a transient loss of vision affecting the upper two-thirds of the right visual field, what are the possible causes?

Transient Vision Loss in Upper Two-Thirds of Right Eye: Differential Diagnosis

This 88-year-old man most likely experienced a branch retinal artery occlusion (BRAO), and requires immediate emergency department evaluation at a stroke center to assess for life-threatening embolic sources and giant cell arteritis (GCA). 1, 2

Most Critical Immediate Considerations

Giant Cell Arteritis (GCA)

• In any patient over 50 years with retinal artery occlusion, GCA must be urgently suspected and can cause permanent bilateral blindness if untreated. 1
• Inquire specifically about jaw claudication, temporal headache, scalp tenderness, polymyalgia rheumatica symptoms, and constitutional symptoms 2
• Check ESR and CRP immediately, though normal inflammatory markers do not exclude GCA 3
• If GCA is suspected or very likely, urgent systemic corticosteroids should be initiated before confirmatory temporal artery biopsy to preserve vision in both eyes 1

Embolic Causes (Most Common in This Age Group)

• Branch retinal artery occlusion from embolic sources is the most likely diagnosis given the sectoral (upper 2/3) pattern of vision loss. 1
• Platelet-fibrin-cholesterol emboli (Hollenhorst plaques) commonly originate from carotid arteries, cardiac valves, or aortic arch 1
• This patient has the same stroke risk as someone with cerebral TIA, with maximum risk in the first 48-72 hours. 2, 3

Complete Differential Diagnosis by Category

Arterial Occlusive Disease

• Branch retinal artery occlusion (BRAO): Sectoral retinal ischemia affecting upper 2/3 of visual field, typically embolic in origin 1
• Central retinal artery occlusion (CRAO): Would cause complete monocular vision loss rather than sectoral 1
• Ophthalmic artery occlusion (OAO): Causes profound vision loss (hand motions or worse) due to both retinal and choroidal ischemia 1

Inflammatory/Vasculitic

• Arteritic retinal artery occlusion from GCA: Can present with sectoral or complete vision loss, triangular areas of choroidal nonperfusion on fluorescein angiography 1
• Other vasculitides (rare in this age without systemic disease) 1

Embolic Sources to Investigate

• Carotid artery stenosis: Large artery atherosclerosis with internal carotid stenosis ≥50% requires urgent identification 2, 3
• Cardiac sources: Atrial fibrillation, valvular disease (especially calcified valves causing calcific emboli), recent myocardial infarction 1, 4
• Aortic arch atheroma 1

Other Vascular Causes

• Hypercoagulable states (less common at age 88, more relevant under age 50) 1
• Ocular ischemic syndrome from severe carotid occlusive disease 4

Benign Causes (Less Likely Given Age and Pattern)

• Retinal migraine: typically younger patients, positive visual phenomena, both eyes affected even if perceived as monocular 4, 5
• Retinal vasospasm: benign, more common in younger patients 4
• Papilledema with transient visual obscurations: bilateral, associated with headache 6

Urgent Management Algorithm

Immediate Actions (Within Hours)

1. Send patient immediately to nearest emergency department affiliated with certified stroke center 2, 3
2. Document as "Ocular TIA" or "Ocular Stroke" on referral 2
3. Check ESR and CRP stat for GCA screening 2, 3

Emergency Department Workup (Within 23-Hour Observation)

• Brain MRI with diffusion-weighted imaging (DWI) to detect acute cerebral infarction 2
• CT angiography or MR angiography of head and neck to identify carotid stenosis 2
• Cardiac monitoring and echocardiography to identify cardioembolic sources 2
• Complete blood count, metabolic panel, lipid panel, hemoglobin A1c 2

Admission Criteria

Hospitalize if presenting within 72 hours AND any of: 2

• Abnormal brain DWI-MRI showing acute cerebral infarction
• Large artery atherosclerosis (internal carotid stenosis ≥50%)
• Abnormal cardiac evaluation revealing embolic source
• Recurrent episodes (crescendo TIAs)
• Inability to provide expedited outpatient follow-up

Secondary Prevention Initiated Immediately

• Antiplatelet therapy (aspirin or dual antiplatelet therapy depending on findings) 2, 3
• High-intensity statin for hyperlipidemia 2
• Blood pressure optimization 2
• Smoking cessation if applicable 1

Critical Pitfalls to Avoid

• Do not dismiss transient symptoms as benign—the stroke risk is highest within 48 hours 3, 7
• Do not delay evaluation for normal inflammatory markers—GCA can present with normal ESR/CRP 3
• Do not assume benign etiology based on transient nature—permanent stroke or blindness may follow 5
• Do not perform only ophthalmologic examination—systemic vascular workup is mandatory 1, 2

Prognosis and Follow-up

• Patients with retinal ischemia have the same cardiovascular event and mortality risk as cerebral TIA patients 3, 5
• Arrange outpatient neurology follow-up within 2 weeks after discharge 2
• Monitor for neovascular complications (iris/retinal neovascularization, neovascular glaucoma) with closer follow-up if greater ischemia present 1
• Panretinal photocoagulation recommended if neovascularization develops 1