Table 5.

Grading Meibomian Gland Expression

Technique	Study Details	Lid Region	Grading Scheme	Reference
Meibum Characteristics
Firm digital pressure	Volume of expressed meibum	Central eight glands of lower eyelid	0 = Normal volume. Just covers orifice 1 = increased to 2 to 3 times normal 2 = increased more than 3 times 3 = increased more than 10 times	Mathers et al.96,97
Firm digital pressure	Viscosity of expressed meibum	Central eight glands of lower eyelid	1 = normal, clear, may have a few particles 2 = opaque with normal viscosity 3 = opaque with increased viscosity 4 = severe thickening (toothpaste)	Mathers et al.96,97
Firm digital pressure	Volume and viscosity of expresssed meibum Clinic-based; referred for dry eye or blepharitis n = 513 total; n = 76 normal women (used to define aqueous deficiency)	Central eight glands of lower eyelid	Obstructive: Viscosity ≥ 3 (1, clear; 2, slightly opaque; 3, thick, opaque; 4, toothpaste Avg. lipid volume: ≤0.3 mm (diameter of expressed lipid in millimeters) Dropout: >0 (presumably examined central eight glands; includes 1/2 and whole glands) Seborrheic: Viscosity: no criteria Avg. lipid volume: >0.7 mm	Mathers et al.96,97 Mathers and Billborough108
Meibum Quality and Expressibility
Firm digital pressure	Quality of meibum	Number of glands not stated	0 = clear fluid 1 = cloudy fluid	Bron et al.75
		UL or LL	2 = cloudy particulate fluid 3 = inspissated, like toothpaste
Firm digital pressure	Expressility of meibum from five glands	UL or LL	0 = all glands expressible 1 = 3–4 glands expressible 2 = 1–2 glands expressible 3 = no glands expressible	Pflugfelder et al.55
Standardized application of pressure	Expression applied to a set of about eight glands	Nasal, central and temporal lid	The MGYLS score is the number of Meibomian Glands out of 8, Yielding Liquid Secretion	Korb and Blackie52 Blackie and Korb81
Meibum Expressibility
Variable digital pressure	Gentle or forceful expression	LL	Analysis of expressed secretion	Henriquez and Korb98
Variable digital pressure	Expressibility of meibum	LL	0 = clear meibum, easily expressed	Shimazaki et al.86,87
			1 = cloudy meibum, easily expressed
			2 = cloudy meibum expressed with moderate pressure
			3 = meibum not expressible, even with hard pressure
Variable digital pressure using the Shimazaki schema	Measurement of lid morphology, expression and meibography	See grading box	Lid margin: Irregular Vascular engorgement Plugged orifices Displacement of MCJ, score “1” for each present	Arita et al.109
	Clinic based n = 53 obstructive MGD subjects n = 60 age-matched controls		Expressed meibum (upper eyelid): 0 = clear, easily expressed 1 = cloudy, mild pressure 2 = cloudy, > moderate pressure 3 = meibum not expressed, with hard pressure
			Meibography: upper and lower eyelids, meiboscore summed (0, no loss; 1, gland loss < 33% of total area; 2, loss = 33–67%; 3, ≥67% loss)