What are the ocular side effects of Amiodarone?

Ocular Side Effects of Amiodarone

Corneal microdeposits (vortex keratopathy/verticillata) occur in nearly all patients on long-term amiodarone therapy and are visible on slit-lamp examination, though they rarely affect vision or require drug discontinuation. 1

Common Ocular Manifestations

Corneal Deposits

• Corneal microdeposits develop in virtually all patients receiving amiodarone for more than 6 months, appearing as a characteristic whorl-like pattern (verticillata) 1, 2
• These deposits result from amiodarone secretion by the lacrimal gland with subsequent accumulation in and absorption by the corneal epithelium 2
• Approximately 10% of patients with corneal deposits become symptomatic, experiencing halos around lights and glare 1, 2
• The deposits seldom affect visual acuity and rarely necessitate discontinuation of the drug 1
• In a systematic review of case reports, cornea verticillata/vortex keratopathy was the most common finding, present in 76% of cases 3

Visual Symptoms

• The most common ocular symptom is colored rings (halos) around lights, reported in 60% of cases in systematic reviews 4, 3
• Patients may experience glare, blurred vision, and decreased visual acuity 1, 4
• Color vision anomalies can occur, particularly when amiodarone is combined with digoxin (which increases digoxin toxicity risk) 4

Serious but Rare Complications

Optic Neuropathy/Neuritis

• Optic neuropathy and optic neuritis have been described in a small number of patients, sometimes progressing to total and permanent blindness 1, 5
• The reported incidence is approximately 1.3-1.8% 6
• A causal relationship is not well established, though temporal associations are documented 1, 5
• Optic neuropathy can occur at any time following initiation of therapy, with reported onset ranging from 5 to 19 months after starting treatment 7
• Cases have been reported with as little as 6.5 weeks of treatment resulting in bilateral, irreversible vision loss 6
• Presentation may include optic disc edema, papilledema, retinal hemorrhages, and visual field defects 7, 3, 6
• Bilateral involvement is common, though unilateral cases occur 7

Acute Corneal Complications

• Acute corneal epithelial edema with cystic eruptions can occur, particularly with rapid dose escalation 2
• Diffuse corneal epithelial edema with fluorescein staining may develop acutely 2

Monitoring and Management Recommendations

Baseline and Ongoing Surveillance

• Baseline ophthalmologic examination is recommended if preexisting visual impairment is present 1
• Regular ophthalmic examination, including fundoscopy and slit-lamp examination, is recommended during amiodarone administration 5
• Ophthalmologic examination should be performed every 6 months for patients on chronic therapy 1, 4

When to Refer for Urgent Evaluation

• Any patient who notes changes in visual acuity or peripheral vision should be referred immediately for ophthalmologic evaluation 1
• If symptoms of visual impairment appear, such as changes in visual acuity and decreases in peripheral vision, prompt ophthalmic examination is recommended 5
• Appearance of optic neuropathy and/or neuritis calls for re-evaluation of amiodarone therapy 5

Treatment Approach

• For symptomatic corneal deposits: symptoms are often dosage-related and usually improve when the dosage is reduced 1, 8
• For acute corneal edema: discontinue or reduce amiodarone, use prophylactic topical antibiotics and supportive preparations (artificial tears/lubricants) 2
• For optic neuropathy: discontinuation of amiodarone is the primary intervention 4, 3
• Visual acuity may improve after drug cessation in some cases, though approximately one-third of patients with optic neuropathy remain asymptomatic and some experience permanent vision loss 6

Clinical Pitfalls

• Do not assume corneal deposits are benign without assessing visual function—while usually asymptomatic, 10% of patients develop significant glare and halos 2
• Be particularly vigilant in elderly patients (>65 years), who appear at higher risk for optic neuropathy 7
• Rapid dose escalation increases risk of acute corneal complications—a case demonstrated acute symptoms after increasing from 100 mg to 300 mg daily 2
• Communicate with prescribing cardiologists promptly when ocular toxicity is identified, as the risks and benefits of continuing therapy must be weighed against life-threatening arrhythmias 5
• Early recognition is imperative to prevent worsening keratopathy or uncommon but severe adverse effects like permanent blindness 3