Which of the following ocular adverse effects is commonly associated with Chloroquine therapy?

• A. Whorl keratopathy
• B. Cotton-wool spots
• C. Optic neuritis
• D. Cataracts

Answer: (A)

Chloroquine commonly causes corneal deposits that create a vortex, or whorl, pattern in the corneal epithelium. This whorl keratopathy is the classic ocular finding with this drug and is often detected on slit-lamp examination. It may be asymptomatic or cause mild visual disturbances, but it is usually reversible or improves with dose adjustment or discontinuation if needed. Other options don’t fit the pattern: cotton-wool spots reflect retinal nerve fiber layer ischemia, optic neuritis involves the optic nerve with vision loss, and cataracts are lens opacities. The key point is that corneal verticillata is the well-known ocular signature of chloroquine therapy.