Acute toxic blindness: unrecognized quinine poisoning

Area of Science:

• Toxicology
• Ophthalmology

Background:

• Quinine, used for malaria and other conditions, can cause toxicity at high doses.
• Accurate diagnosis of quinine toxicity is crucial for timely intervention.

Observation:

• Two cases of acute blindness following quinine ingestion are detailed.
• Patients presented with delayed-onset blindness (over 12 hours post-ingestion).
• Associated symptoms included tinnitus, hearing loss, vomiting, abdominal pain, confusion, and cardiac arrhythmias.

Findings:

• Confirmed quinine poisoning with blood levels significantly exceeding therapeutic range (13.6 and 18.6 µg/mL).
• One patient experienced persistent visual field constriction and reduced acuity.
• The other patient recovered normal visual acuity.

Implications:

• Highlights the potential for delayed and unsuspected visual impairment in quinine toxicity.
• Emphasizes the need for considering quinine poisoning in patients with unexplained visual and neurological symptoms.
• Demonstrates the variable prognosis of quinine-induced visual disturbances.