Meibum quality
MGs secrete meibum, which contains components of the lipid layer of the tear film. The quality of meibum was assessed for the upper and lower eyelids according to the grading schemes: 0, clear (normal); 1, cloudy; 2, cloudy with particles; and 3, inspissated (like toothpaste). A score was recorded only the highest grade encountered from any of central eight glands, and the score range was 0 to 3 [