Table 1.

Tarsal Conjunctival Scarring Grading System

Grade	Definition*
S1	Scarring occupying <1/3 of the upper lid
S1a	One or more pinpoint scars and/or a single line of scarring less than 2 mm in length†
S1b	Multiples lines of scarring less than 2 mm in length
S1c	One or more lines/patches of scarring each 2 mm or more in length/maximal dimension
S2	Patches of scarring occupying in surface area ≥1/3 but <2/3 of the upper lid
3	Patches of scarring occupying in surface area ≥2/3 of the upper lid

^*Upper lid, zones 2 and 3 of the everted upper lid.³

^†2 mm was chosen, as this is the approximate width of the lower lid margin, which is readily available for comparison.