What are the appropriate steps to take if an older adult with a history of glaucoma experiences sudden or severe peripheral vision loss, also known as tunnel vision?

Tunnel Vision in Older Adults with Glaucoma: Emergency Evaluation and Management

An older adult with glaucoma experiencing sudden or severe peripheral vision loss requires immediate emergency department evaluation to rule out acute angle-closure glaucoma, retinal artery occlusion, or retinal detachment—all sight-threatening emergencies that can cause irreversible blindness within hours if untreated. 1, 2

Immediate Triage Decision

Send the patient to the emergency department immediately without attempting outpatient management or delaying transfer to obtain further evaluation. 1 The distinction between chronic glaucoma progression and acute vision-threatening emergencies cannot be reliably made without specialized examination, and the risk of permanent vision loss from delayed treatment is unacceptable. 1, 2

Critical Red Flags Requiring Emergency Evaluation

• Severe unilateral eye pain with vision changes suggests acute angle-closure glaucoma, which has an 18% risk of permanent vision loss if untreated 1
• Cloudy or blurred vision with lacrimation and conjunctival injection indicates corneal edema from elevated intraocular pressure 1
• Nausea and vomiting accompanying eye symptoms is part of the classic triad of acute angle-closure glaucoma 1
• Painless sudden vision loss with curtain-like visual field defect suggests retinal detachment requiring urgent surgical intervention 2
• Painless sudden vision loss in patients with vascular risk factors indicates possible retinal artery occlusion 2

Key Distinguishing Features to Assess

Acute Angle-Closure Glaucoma

• Severe throbbing unilateral pain is the critical distinguishing feature from chronic open-angle glaucoma, which is asymptomatic 1, 3
• Mid-dilated, non-reactive pupil on examination effectively confirms acute angle-closure 4
• Associated systemic symptoms including headache, nausea, and vomiting are common 1, 2

Retinal Artery Occlusion

• Painless sudden vision loss in patients older than 50 years with cardiovascular risk factors 2
• Patients should be evaluated as stroke equivalents with accelerated triage in an emergency center affiliated with a stroke center 5
• High risk for stroke: 2.7% at 1 day, 5.3% at 3 days, 11.5% at 14 days following retinal artery occlusion 5

Giant Cell Arteritis (in patients >50 years)

• Scalp tenderness, jaw claudication, proximal muscle pain with constitutional symptoms 2
• Elevated C-reactive protein, erythrocyte sedimentation rate, and platelet count on laboratory testing 2
• Requires immediate empiric steroids before temporal artery biopsy to prevent vision loss in the contralateral eye 2

Emergency Department Management Protocol

For Suspected Acute Angle-Closure Glaucoma

• Initiate medical therapy immediately to rapidly lower intraocular pressure before definitive laser treatment 1
• Topical beta-blockers, alpha-2 agonists, topical or systemic carbonic anhydrase inhibitors, and systemic hyperosmotic agents should be administered 1
• Definitive treatment is laser peripheral iridotomy (LPI) performed as soon as the cornea clears enough to visualize the iris 1
• The fellow eye requires prophylactic laser iridotomy due to similar anatomic predisposition 1

For Suspected Retinal Artery Occlusion

• Neuroimaging within 24 hours of symptom onset, preferably MRI with diffusion-weighted imaging 5
• Noninvasive imaging of cervicocephalic vessels (MRA, CTA, or carotid ultrasound) should be performed routinely 5
• Electrocardiography immediately with prolonged cardiac monitoring if etiology unclear 5
• Echocardiography is reasonable, especially when no cause identified by other workup 5

For Suspected Retinal Detachment

• Surgical intervention is usually required and should not be delayed 2
• Ophthalmology consultation should occur emergently in the emergency department 2

Critical Pitfalls to Avoid

• Do not assume this is chronic glaucoma progression simply because the patient has a glaucoma history—chronic open-angle glaucoma is asymptomatic and progresses slowly 3, 6
• Do not dismiss severe pain as "just conjunctivitis" because of lacrimation and redness—conjunctivitis does not cause severe pain or cloudy vision 1
• Do not start topical corticosteroids before ophthalmologic examination, as this can worsen certain conditions and mask accurate diagnosis 1
• Do not delay transfer for outpatient ophthalmology appointment—the time window for effective treatment is measured in hours, not days 1, 2

Risk Stratification for Chronic Glaucoma Patients

While the above focuses on emergencies, it's important to note that patients with established glaucoma remain at risk for disease progression:

• Elevated intraocular pressure remains the only modifiable risk factor for glaucoma progression 6, 7
• Regular monitoring with perimetry and optical coherence tomography is essential to detect progression 7
• Medication adherence is crucial—noncompliance, adverse effects, and cost frequently limit effectiveness 6

When Chronic Progression is More Likely

If the patient reports gradual worsening over weeks to months without pain, this suggests chronic glaucoma progression rather than an acute emergency 3. However, even in this scenario, same-day or next-day ophthalmology evaluation is warranted to assess for treatment intensification, as untreated open-angle glaucoma can end in irreversible vision loss 3.