Corneal Scarring - End Stage Trachoma
  • Most common cause of infectious blindness worldwide
  • Caused by Chlamydia trachomatis
    • Spread by direct contact, fomites (towels, clothes, bed covers), and flies (those that have landed on or near the mouth or eyes of other infected individuals)
  • More than 6 million blind secondary to trachoma and more than 150 million in need of treatment
  • Typically affects most marginalized populations in the world

Clinical Features


  • Conjunctivitis-like symptoms
    • Conjunctival follicles (white lumps) on the inner upper eyelid
    • Non-specific inflammation and thickening of the conjunctiva


  • Known as the "quiet disease" because of its slow chronic course
  • Blindness after repeated infections
    • Caused by structural changes to the inner eyelid
      • Scarring of the inner eyelid that leads to buckling of the lid
        • This causes the eyelashes to turn inwards (Trichiasis) and rub on the cornea causing repetitive trauma that leads to opacities and scarring of the cornea
  • Major complications include corneal ulcers

Differential Diagnosis


  • Clinical diagnosis

WHO classification

  • Simplified grading system composed of 5 clinical signs of infection
    • Follicular trachomatous inflammation (TF)
      • ≥5 follicles >0.5mm on the superior tarsal conjunctiva
    • Intense trachomatous inflammation (TI)
      • Hypertrophy of the papilla and inflammatory thickening of the superior tarsal conjunctiva (must obscure more than half of the deep vessels)
    • Trachomatous scarring (TS)
      • Scarring in the superior tarsal conjunctiva
    • Trachomatous trichiasis (TT)
      • One or more ingrown eyelash in contact with the globe or evidence of eyelash loss (epilation)
    • Corneal opacity
      • Must blur part of the pupil margin


  • S.A.F.E. strategy proposed by WHO
    • S - Surgery
      • Bilamellar tarsal rotation procedure recommended by WHO
    • A - Antibiotics
      • Tetracycline 1% eye ointment
        • Adherence issues secondary to difficulty in use and uncomfortable to apply
      • Azithromycin (20mg/kg) single dose
        • Relatively expensive in resource poor settings
    • F - Facial cleanliness
      • Helps decrease disease transmission
    • E - Environmental management
      • WHO emphasizes access to latrine and clean water


See Also