II. Epidemiology
- Trachoma is responsible for 15% of world blindness (most common cause of preventable blindness)
- Highest risk of Trachoma in first 3-6 years of life
- Children are the primary reservoir of the disease
- Trachoma is a disease of poverty
- Affects socioeconomically disadvantaged populations and developing nations
- Although rare in the U.S., native americans are most often affected
III. History
- Trachoma was first described in 16th Century B.C. Egypt
IV. Pathophysiology
- See Chlamydiaceae
- Organism: Chlamydia Trachomatis subtypes A-C
- Contrast with subtypes D to K (e.g. Cervicitis, Inclusion Conjunctivitis, Neonatal Pneumonia)
- Contrast with subtypes L1 to 3 (Lymphogranuloma venereum)
- Transmitted by hand to hand contact
- Typically transmitted between children by hand-to-hand contact of eye secretions
- Also transmitted when sharing contaminated clothing or towels
-
Conjunctival scarring (Cicatricial Trachoma)
- Chronic follicular Conjunctivitis
- Chronic inflammation from recurrent infection
- Scarring complete by young adulthood (develops slowly over 10-15 years)
V. Findings
- Conjunctival injection and inflammation leading to gradual Conjunctival scarring
-
Eyelid is is inverted inward due to scar traction
- Eyelashes chronically scrape the Conjunctiva and Corneal surface
- Chronic Corneal Abrasions lead to Bacterial Conjunctivitis and scarring
- Progressively Decreased Visual Acuity
- Blindness develops gradually over 10-15 years (typically by adulthood)
VI. Labs
- Intracytoplasmic Inclusion Bodies
- Historically used to identify Chlamydia Conjunctivitis (replaced by PCR)
- Responsible for the Chlamydial Conjunctivitis naming (Inclusion Conjunctivitis)
- However, Trachoma inclusion bodies are indistinguishable from those in Chlamydia Conjunctivitis
- Microscopy of cell scrapings from the palpebral Conjunctiva (inner Eyelid lining)
- Small Basophilic (deep purple) inclusion bodies seen within Conjunctival cells
- An inclusion body is a Chlamydia Initial Body (Chlamydia Reticulate Body)
- Historically used to identify Chlamydia Conjunctivitis (replaced by PCR)
VII. Management
- Azithromycin 20 mg/kg orally (up to 1 gram) for single dose (or Doxycycline 100 mg orally twice daily for 21 days) AND
- Topical Tetracycline or Erythromycin ointment twice daily for 28 days
VIII. References
- Williams (2017) Crit Dec Emerg Med 31(2): 3-12
- Yanoff (1999) Ophthalmology, Mosby, p. 1.7
- Katusik (2003) Am J Ophthalmol 135(4): 447-51 [PubMed]
- Lietman (1999) Ophthalmol Clin North Am 12(1) [PubMed]
- Mabey (2005) Cochrane Database Syst Rev (2): CD001860 [PubMed]