Xiao J, Adil MY, Chen X, et al. - In this cross-sectional study, researchers classified subtypes of meibomian gland dysfunction (MGD) and assessed the dependency of dry eye signs, symptoms and parameters with MGD subtype. The study population consisted of the right eyes of 447 patients with MGD of various subtypes and 20 healthy volunteers. Investigators found that low-delivery MGD patients had worse dry eye parameters and ocular symptoms than those with elevated meibum delivery, suggesting the pivotal role of meibum secretion in ocular surface health that should be aimed in MGD treatment. In addition, non-obvious MGD can not be diagnosed using traditional dry eye tests and needs morphologic evaluation of meibography images to verify meibomian gland loss.