SEARCH RESULTS FOR: Trachoma

Trachoma

Trachoma: Pathogenesis and ocular manifestations Risk factors for infection Mode of transmission Authors: Palak Sharma, Helena Zakrzewski Reviewers: Prima Moinul, Riley Hartman Emily J. Doucette, Edsel Ing* * MD at time of publication Crowded living conditions Poor hygiene practices Limited access to sanitary facilities Direct contact with ocular & nasal secretions of infected individuals Indirect contact with fomites (contaminated objects or surfaces) Mechanical vectors: Eye-seeking flies (e.g. Musca sorbens) Chlamydia trachomatis infection (serotype A, B & C) Trachoma Chronic keratoconjunctivitis (inflammation of the conjunctiva & cornea) caused by recurrent infection with C. trachomatis Active Phase Bacteria infects the conjunctival epithelial cells Redness, irritation & mucopurulent discharge Immune response triggers inflammation of the upper tarsal conjunctiva Herbert’s pits (small, sunken scars at the limbus (border between cornea & sclera) from healed follicles Corneal lesions Pannus (invasion by superficial vessels) at the limbus Lymphoid follicles consisting mainly of B & T cells form in the upper tarsal conjunctiva Trachomatous inflammation - follicular: Presence of five or more white or yellow follicles, each 0.5 mm or bigger in size Inflammation leads to papillae formation with dilated blood vessels, infiltration of lymphocytes, plasma cells & neutrophils & proliferation of epithelial cells Small, raised bumps with a central blood vessel in the upper conjunctiva Papillary hypertrophy causes conjunctival thickening & opaqueness Trachomatous inflammation - intense: Papillae obscure deep tarsal blood vessels Repeated re-infection or untreated infections Cicatricial (scarring) Phase Proliferation of fibroblasts & deposition of collagen leads to scarring (fibrosis) Trachomatous scarring: White, horizontal lines or bands on upper tarsal conjunctiva Scarring blocks meibomian gland ducts Conjunctival epithelium atrophy & goblet cell destruction Subconjunctival fibrosis Entropion (eyelid turns inward) Cornea ulcers & scarring ↑ Tear evaporation ↓ Tear production Scar contraction distorts upper tarsal plate Dry eye Trachomatous trichiasis (eyelashes grow inward toward the eye) Corneal abrasion Corneal opacity & blindness Published Sept, 2 2015; updated May 7, 2025 on www.thecalgaryguide.com Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications