WHO simplified trachoma grading system

TF Trachomatous Inflammation - Follicular.
The presence of five or more follicles in the upper tarsal conjunctiva. Photo: John Anderson
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TI Trachomatous Inflammation - Intense.
Pronounced inflammatory thickening of the tarsal conjunctiva that obscures more than half of the normal deep tarsal vessels. Photo: Allen Foster
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TS Trachomatous Scarring.
The presence of scarring in the tarsal conjunctiva. Photo: Hugh Taylor
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TT Trachomatous Trichiasis.
At least one eyelash rubs on the eyeball or evidence of recent removal of inturned eyelashes. Photo: WHO
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CO Corneal Opacity.
Easily visible corneal opacity over the pupil. Photo: John Anderson
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