**3.7 Meibum gland (MG)**

The quality of the meibum was assessed by expressing the meibomian glands with the Meibomian Gland Evaluator (MGE; Tear Science, Inc., Morrisville, NC), a standardized instrument developed by Korb et al., and then evaluating the quality of meibomian secretions [16]. MGE was applied for 15 glands (5 nasal+5 central+5 temporals) along the lower eyelid. For each gland, the examiner sub-scored the quality of the expressed meibum using a four-point scale: 0 (no secretion), 1 (inspissated or toothpaste-like secretion), 2 (cloudy liquid secretion), or 3 (clear liquid secretion). The sum of this 15 subs-cores, ranging from 0 to 45, defined the Meibomian Gland Yielding Secretion Score (MGYSS). MGYSS was evaluated at BL and FU [1].
