Fluorescence staining (FL)
CORNEA
The range of fluorescein staining was observed under the cobalt blue light of the slit lamp microscope after placing the 2% sodium fluorescein staining test paper into the subject’s conjunctival sac of the lower eyelid. The cornea was divided into four quadrants: supratemporal, infratemporal, supranasal, and infranasal. The score was evaluated in every quadrant. The scoring criteria were as follows: 0 for no coloring, 1 for scattered punctate coloring, 2 for diffuse punctate coloring, and 3 for massive coloring. The sum of the scores in each quadrant constituted the corneal FL score with a total of 0–12 points.