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