Trachoma causes blindness through which pathological mechanism?

• A Scarring of the tarsal conjunctiva leading to trichiasis and entropion, causing mechanical corneal abrasion and eventual corneal opacification ✓
• B Direct corneal destruction by Chlamydia trachomatis
• C Optic neuritis caused by spread of infection along the optic nerve
• D Uveitis and secondary glaucoma

Explanation

Trachoma (C. trachomatis serovars A, B, Ba, C) is the leading infectious cause of blindness globally. Repeated cycles of infection cause conjunctival scarring (arlt's line, Herbert's pits), tarsal conjunctival fibrosis, and ultimately cicatricial entropion (lid turns in) with trichiasis (lashes rubbing cornea). This mechanical abrasion causes corneal ulceration, vascularization (pannus), and opacification — the ultimate blinding stage. The organism does not directly destroy the cornea. WHO SAFE strategy (Surgery, Antibiotics, Facial cleanliness, Environmental improvement) addresses each stage.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.