In Vivo Laser Scanning Confocal Microscopy of Human Meibomian Glands in Aging and Ocular Surface Diseases

Table 1

Summary of the most important confocal signs for each disease affecting MGs.

Conditions	LSCM characteristics	References
Aging	MG acinar unit density and diameter reduction; increase of the acinar wall inhomogeneity	[13, 15, 16, 24, 25]
MGD	MG acinar unit density reduction; larger acinar unit diameter; duct dilation	[26–31]
Dry eye	MG acinar unit density and diameter reduction; inhomogeneous appearance of the MG walls and interstices; extensive periglandular Langerhans cell infiltration	[13, 16, 24, 25, 32–35]
Ocular allergy	Eosinophils and multinucleated granulocytes in the superficial conjunctival epithelium; periglandular lymphocytic cell infiltration; glandular atrophy and acinar and ductal dilatation	[13, 16, 24, 25, 36–39]
Glaucoma	MG acinar unit density and area reduction; increased reflectivity of the acinar secretion; ductal orifice dilation; inhomogeneity of MG interstice and wall	[9, 40]