Chlamydial trachoma causes blindness primarily through which sequence of pathological changes?

• A Direct corneal invasion by Chlamydia trachomatis causing stromal ulceration
• B Pannus formation occluding the pupil directly
• C Conjunctival scarring → tarsal fibrosis → entropion → trichiasis → corneal abrasion and scarring ✓
• D Secondary bacterial conjunctivitis spreading to the cornea

Explanation

Trachoma causes blindness via a cascade: repeated Chlamydia infection triggers chronic conjunctival inflammation, forming follicles and Herbert's pits (scarred follicles at limbus). Progressive subconjunctival scarring (Arlt's line on tarsal conjunctiva) causes tarsal fibrosis and upper lid entropion, which turns eyelashes inward (trichiasis). Repeated corneal trauma from lashes, compounded by secondary infections, produces corneal scarring and opacity. The SAFE strategy (Surgery, Antibiotics, Facial cleanliness, Environmental improvement) targets this cascade.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.