Which ocular infection is the leading cause of preventable blindness worldwide?

• A. Ophthalmia neonatorum
• B. Trachoma
• C. Inclusion conjunctivitis
• D. Bacterial conjunctivitis

Answer: (B)

Trachoma is the leading cause of preventable blindness worldwide. It starts with repeated infection by Chlamydia trachomatis, especially in crowded or unsanitary living conditions. This ongoing inflammation steadily scars the inner surface of the eyelid (the tarsal conjunctiva). As the eyelids become scarred, they can turn inward (entropion) and the eyelashes rub against the cornea (trichiasis), damaging the corneal surface and leading to vision loss. The situation is preventable and often reversible in the early stages, and public health efforts focus on the SAFE strategy: Surgery for the eyelid deformity, Antibiotics to clear infection, Facial cleanliness, and Environmental improvements to reduce transmission. The other infections listed can cause conjunctivitis, but they do not typically cause the chronic eyelid scarring and corneal damage that drive trachoma-related blindness, so trachoma is the correct choice.