Fig. 4. Mild conjunctival scarring in a case of healed (inactive) trachoma. The scars appear as fine white lines (C1) (see Table 1). The yellow aggregations are subconjunctival cysts. These cysts (known as posttrachomatous degeneration) are formed by epithelium trapped below the surface by scars. The yellow cheesey material in the cysts is formed by desquamated epithelium, which often extrudes onto the conjunctival surface. The dark notches in the upper limbus are Herbert's pits, the depressions left by limbal follicles in childhood.