A 7-year-old child from a rural area presents with bilateral tarsal conjunctival scarring (Arlt's lines), Herbert's pits at the limbus, and corneal pannus formation. The WHO grading for this patient would include:

• A TF (Trachomatous follicles) alone — early active disease
• B TI (Trachomatous intense inflammation) with TF
• C TT (Trachomatous trichiasis) with TS
• D TS (Trachomatous scarring) with CO (Corneal opacity) ✓

Explanation

The WHO simplified grading system for trachoma: TF = ≥5 follicles on upper tarsal conjunctiva (active); TI = intense inflammatory thickening obscuring ≥50% of deep tarsal vessels (active); TS = scarring (Arlt's lines, Herbert's pits indicate scarring sequelae); TT = trichiasis (eyelashes touching globe); CO = corneal opacity over pupil causing visual impairment. This patient has tarsal scars (TS), Herbert's pits (limbal scars from resolved follicles), and pannus (CO). Pannus from trachoma is superior (top of cornea) — distinguishing it from pannus from other causes.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.