Figure 1.

Measurement of corneal epithelial thickness (CET, upper) and maximal limbal epithelial thickness (mLET, lower) by using anterior segment optical coherence tomography (OCT). The center of the cornea and 2 points at 1 mm away from the center of the cornea were located (Upper left). CET was measured at these 3 locations from a point beneath the tear film (first hyperreflective layer) to the basal membrane (second hyperreflective layer). The value of CET in the center of the cornea was OCT-CET1, and the mean of these 3 points was OCT-CET3. “Line a” is perpendicular to the tangent of the limbal surface, which crosses the scleral spur (SS); “line b” is a connecting line between the ending points of Bowman’s layer and Descemet’s membrane. The limbal epithelium area (LEA) is defined by 2 white solid lines (“line a” and “line b”). The thickest part of the LEA was located, and the mLET was measured.