Which is the most common ocular adverse effect of hydroxychloroquine therapy?

• A. Impaired Night Vision
• B. Jaundice
• C. Proteinuria
• D. Mouth Sores

Answer: (A)

Hydroxychloroquine can affect the eyes because it can accumulate in ocular tissues, leading to changes in vision from corneal deposits to retinal toxicity with longer-term use. Among the options provided, the only one that describes an ocular symptom is impaired night vision, which makes it the best choice in this context. The other options point to non-ocular organ effects (jaundice from liver involvement, proteinuria from kidney involvement, and mouth sores from mucosal irritation), which aren’t about the eyes. In clinical practice, any new visual disturbance in a patient on hydroxychloroquine should prompt an eye exam, since corneal changes are common and retinal toxicity can be more serious, though these typically present as central vision changes rather than night-blooming issues.